indent(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | INVOKING INDENT | BACKUP FILES | COMMON STYLES | BLANK LINES | --blank-lines-after-declarations | --blank-lines-after-procedures | COMMENTS | STATEMENTS | DECLARATIONS | INDENTATION | BREAKING LONG LINES | DISABLING FORMATTING | MISCELLANEOUS OPTIONS | BUGS | COPYRIGHT | Options’ Cross Key | RETURN VALUE | FILES | AUTHORS | HISTORY | COPYING | COLOPHON

INDENT(1L)                                                    INDENT(1L)

NAME         top

       indent - changes the appearance of a C program by inserting or
       deleting whitespace.

SYNOPSIS         top

       indent [options] [input-files]

       indent [options] [single-input-file] [-o output-file]

       indent --version

DESCRIPTION         top

       This man page is generated from the file indent.texinfo.  This is
       Edition  of "The indent Manual", for Indent Version , last
       updated .

       The indent program can be used to make code easier to read.  It
       can also convert from one style of writing C to another.

       indent understands a substantial amount about the syntax of C,
       but it also attempts to cope with incomplete and misformed
       syntax.

       In version 1.2 and more recent versions, the GNU style of
       indenting is the default.

OPTIONS         top

       -bad, --blank-lines-after-declarations
           Force blank lines after the declarations.
           See  BLANK LINES.

       -bap, --blank-lines-after-procedures
           Force blank lines after procedure bodies.
           See  BLANK LINES.

       -bbb, --blank-lines-before-block-comments
           Force blank lines before block comments.
           See  BLANK LINES.

       -bbo, --break-before-boolean-operator
           Prefer to break long lines before boolean operators.
           See  BREAKING LONG LINES.

       -bc, --blank-lines-after-commas
           Force newline after comma in declaration.
           See  DECLARATIONS.

       -bl, --braces-after-if-line
           Put braces on line after if, etc.
           See  STATEMENTS.

       -blf, --braces-after-func-def-line
           Put braces on line following function definition line.
           See  DECLARATIONS.

       -blin, --brace-indentn
           Indent braces n spaces.
           See  STATEMENTS.

       -bls, --braces-after-struct-decl-line
           Put braces on the line after struct declaration lines.
           See  DECLARATIONS.

       -br, --braces-on-if-line
           Put braces on line with if, etc.
           See  STATEMENTS.

       -brf, --braces-on-func-def-line
           Put braces on function definition line.
           See  DECLARATIONS.

       -brs, --braces-on-struct-decl-line
           Put braces on struct declaration line.
           See  DECLARATIONS.

       -bs, --Bill-Shannon, --blank-before-sizeof
           Put a space between sizeof and its argument.
           See  STATEMENTS.

       -cn, --comment-indentationn
           Put comments to the right of code in column n.
           See  COMMENTS.

       -cbin, --case-brace-indentationn
           Indent braces after a case label N spaces.
           See  STATEMENTS.

       -cdn, --declaration-comment-columnn
           Put comments to the right of the declarations in column n.
           See  COMMENTS.

       -cdb, --comment-delimiters-on-blank-lines
           Put comment delimiters on blank lines.
           See  COMMENTS.

       -cdw, --cuddle-do-while
           Cuddle while of do {} while; and preceding ‘}’.
           See  COMMENTS.

       -ce, --cuddle-else
           Cuddle else and preceding ‘}’.
           See  COMMENTS.

       -cin, --continuation-indentationn
           Continuation indent of n spaces.
           See  STATEMENTS.

       -clin, --case-indentationn
           Case label indent of n spaces.
           See  STATEMENTS.

       -cpn, --else-endif-columnn
           Put comments to the right of #else and #endif statements in
           column n.
           See  COMMENTS.

       -cs, --space-after-cast
           Put a space after a cast operator.
           See  STATEMENTS.

       -dn, --line-comments-indentationn
           Set indentation of comments not to the right of code to n
           spaces.
           See  COMMENTS.

       -bfda, --break-function-decl-args
           Break the line before all arguments in a declaration.
           See  DECLARATIONS.

       -bfde, --break-function-decl-args-end
           Break the line after the last argument in a declaration.
           See  DECLARATIONS.

       -dj, --left-justify-declarations
           If -cd 0 is used then comments after declarations are left
           justified behind the declaration.
           See  DECLARATIONS.

       -din, --declaration-indentationn
           Put variables in column n.
           See  DECLARATIONS.

       -fc1, --format-first-column-comments
           Format comments in the first column.
           See  COMMENTS.

       -fca, --format-all-comments
           Do not disable all formatting of comments.
           See  COMMENTS.

       -fnc, --fix-nested-comments
           Fix nested comments.
           See  COMMENTS.

       -gnu, --gnu-style
           Use GNU coding style.  This is the default.
           See  COMMON STYLES.

       -gts, --gettext-strings
           Treat gettext _("...") and N_("...") as strings rather than
           as functions.
           See  BREAKING LONG LINES.

       -hnl, --honour-newlines
           Prefer to break long lines at the position of newlines in the
           input.
           See  BREAKING LONG LINES.

       -in, --indent-leveln
           Set indentation level to n spaces.
           See  INDENTATION.

       -iln, --indent-labeln
           Set offset for labels to column n.
           See  INDENTATION.

       -ipn, --parameter-indentationn
           Indent parameter types in old-style function definitions by n
           spaces.
           See  INDENTATION.

       -kr, --k-and-r-style
           Use Kernighan & Ritchie coding style.
           See  COMMON STYLES.

       -ln, --line-lengthn
           Set maximum line length for non-comment lines to n.
           See  BREAKING LONG LINES.

       -lcn, --comment-line-lengthn
           Set maximum line length for comment formatting to n.
           See  COMMENTS.

       -linux, --linux-style
           Use Linux coding style.
           See  COMMON STYLES.

       -lp, --continue-at-parentheses
           Line up continued lines at parentheses.
           See  INDENTATION.

       -lps, --leave-preprocessor-space
           Leave space between ‘#’ and preprocessor directive.
           See  INDENTATION.

       -nbad, --no-blank-lines-after-declarations
           Do not force blank lines after declarations.
           See  BLANK LINES.

       -nbap, --no-blank-lines-after-procedures
           Do not force blank lines after procedure bodies.
           See  BLANK LINES.

       -nbbo, --break-after-boolean-operator
           Do not prefer to break long lines before boolean operators.
           See  BREAKING LONG LINES.

       -nbc, --no-blank-lines-after-commas
           Do not force newlines after commas in declarations.
           See  DECLARATIONS.

       -nbfda, --dont-break-function-decl-args
           Don’t put each argument in a function declaration on a
           separate line.
           See  DECLARATIONS.

       -ncdb, --no-comment-delimiters-on-blank-lines
           Do not put comment delimiters on blank lines.
           See  COMMENTS.

       -ncdw, --dont-cuddle-do-while
           Do not cuddle } and the while of a do {} while;.
           See  STATEMENTS.

       -nce, --dont-cuddle-else
           Do not cuddle } and else.
           See  STATEMENTS.

       -ncs, --no-space-after-casts
           Do not put a space after cast operators.
           See  STATEMENTS.

       -ndjn, --dont-left-justify-declarations
           Comments after declarations are treated the same as comments
           after other statements.
           See  DECLARATIONS.

       -nfc1, --dont-format-first-column-comments
           Do not format comments in the first column as normal.
           See  COMMENTS.

       -nfca, --dont-format-comments
           Do not format any comments.
           See  COMMENTS.

       -ngts, --no-gettext-strings
           Treat gettext _("...") and N_("...") as normal functions.
           This is the default.
           See  BREAKING LONG LINES.

       -nhnl, --ignore-newlines
           Do not prefer to break long lines at the position of newlines
           in the input.
           See  BREAKING LONG LINES.

       -nip, --no-parameter-indentation
           Zero width indentation for parameters.
           See  INDENTATION.

       -nlp, --dont-line-up-parentheses
           Do not line up parentheses.
           See  STATEMENTS.

       -npcs, --no-space-after-function-call-names
           Do not put space after the function in function calls.
           See  STATEMENTS.

       -nprs, --no-space-after-parentheses
           Do not put a space after every ’(’ and before every ’)’.
           See  STATEMENTS.

       -npsl, --dont-break-procedure-type
           Put the type of a procedure on the same line as its name.
           See  DECLARATIONS.

       -nsaf, --no-space-after-for
           Do not put a space after every for.
           See  STATEMENTS.

       -nsai, --no-space-after-if
           Do not put a space after every if.
           See  STATEMENTS.

       -nsaw, --no-space-after-while
           Do not put a space after every while.
           See  STATEMENTS.

       -nsc, --dont-star-comments
           Do not put the ‘*’ character at the left of comments.
           See  COMMENTS.

       -nsob, --leave-optional-blank-lines
           Do not swallow optional blank lines.
           See  BLANK LINES.

       -nss, --dont-space-special-semicolon
           Do not force a space before the semicolon after certain
           statements.  Disables ‘-ss’.
           See  STATEMENTS.

       -nut, --no-tabs
           Use spaces instead of tabs.
           See  INDENTATION.

       -nv, --no-verbosity
           Disable verbose mode.
           See  MISCELLANEOUS OPTIONS.

       -orig, --original
           Use the original Berkeley coding style.
           See  COMMON STYLES.

       -npro, --ignore-profile
           Do not read ‘.indent.pro’ files.
           See  INVOKING INDENT.

       -pal, --pointer-align-left
           Put asterisks in pointer declarations on the left of spaces,
           next to types: ‘‘char* p’’.

       -par, --pointer-align-right
           Put asterisks in pointer declarations on the right of spaces,
           next to variable names: ‘‘char *p’’. This is the default
           behavior.

       -pcs, --space-after-procedure-calls
           Insert a space between the name of the procedure being called
           and the ‘(’.
           See  STATEMENTS.

       -pin, --paren-indentationn
           Specify the extra indentation per open parentheses ’(’ when a
           statement is broken.See  STATEMENTS.

       -pmt, --preserve-mtime
           Preserve access and modification times on output files.See
            MISCELLANEOUS OPTIONS.

       -ppin, --preprocessor-indentationn
           Specify the indentation for preprocessor conditional
           statements.See  INDENTATION.

       -prs, --space-after-parentheses
           Put a space after every ’(’ and before every ’)’.
           See  STATEMENTS.

       -psl, --procnames-start-lines
           Put the type of a procedure on the line before its name.
           See  DECLARATIONS.

       -saf, --space-after-for
           Put a space after each for.
           See  STATEMENTS.

       -sai, --space-after-if
           Put a space after each if.
           See  STATEMENTS.

       -saw, --space-after-while
           Put a space after each while.
           See  STATEMENTS.

       -sbin, --struct-brace-indentationn
           Indent braces of a struct, union or enum N spaces.
           See  STATEMENTS.

       -sc, --start-left-side-of-comments
           Put the ‘*’ character at the left of comments.
           See  COMMENTS.

       -sob, --swallow-optional-blank-lines
           Swallow optional blank lines.
           See  BLANK LINES.

       -ss, --space-special-semicolon
           On one-line for and while statements, force a blank before
           the semicolon.
           See  STATEMENTS.

       -st, --standard-output
           Write to standard output.
           See  INVOKING INDENT.

       -T  Tell indent the name of typenames.
           See  DECLARATIONS.

       -tsn, --tab-sizen
           Set tab size to n spaces.
           See  INDENTATION.

       -ut, --use-tabs
           Use tabs. This is the default.
           See  INDENTATION.

       -v, --verbose
           Enable verbose mode.
           See  MISCELLANEOUS OPTIONS.

       -version
           Output the version number of indent.
           See  MISCELLANEOUS OPTIONS.

INVOKING INDENT         top

       As of version 1.3, the format of the indent command is:

            indent [options] [input-files]

            indent [options] [single-input-file] [-o output-file]

       This format is different from earlier versions and other versions
       of indent.

       In the first form, one or more input files are specified.  indent
       makes a backup copy of each file, and the original file is
       replaced with its indented version.  See BACKUP FILES, for an
       explanation of how backups are made.

       In the second form, only one input file is specified.  In this
       case, or when the standard input is used, you may specify an
       output file after the ‘-o’ option.

       To cause indent to write to standard output, use the ‘-st’
       option.  This is only allowed when there is only one input file,
       or when the standard input is used.

       If no input files are named, the standard input is read for
       input.  Also, if a filename named ‘-’ is specified, then the
       standard input is read.

       As an example, each of the following commands will input the
       program ‘slithy_toves.c’ and write its indented text to
       ‘slithy_toves.out’:

            indent slithy_toves.c -o slithy_toves.out

            indent -st slithy_toves.c > slithy_toves.out

            cat slithy_toves.c | indent -o slithy_toves.out

       Most other options to indent control how programs are formatted.
       As of version 1.2, indent also recognizes a long name for each
       option name.  Long options are prefixed by either ‘--’ or ‘+’.  [
       ‘+’ is being superseded by ‘--’ to maintain consistency with the
       POSIX standard.]
        In most of this document, the traditional, short names are used
       for the sake of brevity.  See OPTION SUMMARY, for a list of
       options, including both long and short names.

       Here is another example:

            indent -br test/metabolism.c -l85

       This will indent the program ‘test/metabolism.c’ using the ‘-br’
       and ‘-l85’ options, write the output back to ‘test/metabolism.c’,
       and write the original contents of ‘test/metabolism.c’ to a
       backup file in the directory ‘test’.

       Equivalent invocations using long option names for this example
       would be:

            indent --braces-on-if-line --line-length185 test/metabolism.c

            indent +braces-on-if-line +line-length185 test/metabolism.c

       If you find that you often use indent with the same options, you
       may put those options into a file named ‘.indent.pro’.  indent
       will look for a profile file in three places. First it will check
       the environment variable INDENT_PROFILE. If that exists its value
       is expected to name the file that is to be used. If the
       environment variable does not exist, indent looks for
       ‘.indent.pro’ in the current directory
        and use that if found.  Finally indent will search your home
       directory for ‘.indent.pro’ and use that file if it is found.
       This behaviour is different from that of other versions of
       indent, which load both files if they both exist.

       The format of ‘.indent.pro’ is simply a list of options, just as
       they would appear on the command line, separated by white space
       (tabs, spaces, and newlines).  Options in ‘.indent.pro’ may be
       surrounded by C or C++ comments, in which case they are ignored.

       Command line switches are handled after processing ‘.indent.pro’.
       Options specified later override arguments specified earlier,
       with one exception: Explicitly specified options always override
       background options (See COMMON STYLES).  You can prevent indent
       from reading an ‘.indent.pro’ file by specifying the ‘-npro’
       option.

BACKUP FILES         top

       As of version 1.3, GNU indent makes GNU-style backup files, the
       same way GNU Emacs does.  This means that either simple or
       numbered backup filenames may be made.

       Simple backup file names are generated by appending a suffix to
       the original file name.  The default for this suffix is the one-
       character string ‘~’ (tilde).  Thus, the backup file for
       ‘python.c’ would be ‘python.c~’.

       Instead of the default, you may specify any string as a suffix by
       setting the environment variable SIMPLE_BACKUP_SUFFIX to your
       preferred suffix.

       Numbered backup versions of a file ‘momeraths.c’ look like
       ‘momeraths.c.~23~’, where 23 is the version of this particular
       backup.  When making a numbered backup of the file
       ‘src/momeraths.c’, the backup file will be named
       ‘src/momeraths.c.~V~’, where V is one greater than the highest
       version currently existing in the directory ‘src’.  The
       environment variable VERSION_WIDTH controls the number of digits,
       using left zero padding when necessary.  For instance, setting
       this variable to "2" will lead to the backup file being named
       ‘momeraths.c.~04~’.

       The type of backup file made is controlled by the value of the
       environment variable VERSION_CONTROL.  If it is the string
       ‘simple’, then only simple backups will be made.  If its value is
       the string ‘numbered’, then numbered backups will be made.  If
       its value is ‘numbered-existing’, then numbered backups will be
       made if there already exist numbered backups for the file being
       indented; otherwise, a simple backup is made.  If VERSION_CONTROL
       is not set, then indent assumes the behaviour of ‘numbered-
       existing’.

       Other versions of indent use the suffix ‘.BAK’ in naming backup
       files.  This behaviour can be emulated by setting
       SIMPLE_BACKUP_SUFFIX to ‘.BAK’.

       Note also that other versions of indent make backups in the
       current directory, rather than in the directory of the source
       file as GNU indent now does.

COMMON STYLES         top

       There are several common styles of C code, including the GNU
       style, the Kernighan & Ritchie style, and the original Berkeley
       style.  A style may be selected with a single background option,
       which specifies a set of values for all other options.  However,
       explicitly specified options always override options implied by a
       background option.

       As of version 1.2, the default style of GNU indent is the GNU
       style.  Thus, it is no longer necessary to specify the option
       ‘-gnu’ to obtain this format, although doing so will not cause an
       error.  Option settings which correspond to the GNU style are:

            -nbad -bap -nbc -bbo -bl -bli2 -bls -ncdb -nce -cp1 -cs -di2
            -ndj -nfc1 -nfca -hnl -i2 -ip5 -lp -pcs -nprs -psl -saf -sai
            -saw -nsc -nsob

       The GNU coding style is that preferred by the GNU project.  It is
       the style that the GNU Emacs C mode encourages and which is used
       in the C portions of GNU Emacs.  (People interested in writing
       programs for Project GNU should get a copy of "The GNU Coding
       Standards", which also covers semantic and portability issues
       such as memory usage, the size of integers, etc.)

       The Kernighan & Ritchie style is used throughout their well-known
       book "The C Programming Language".  It is enabled with the ‘-kr’
       option.  The Kernighan & Ritchie style corresponds to the
       following set of options:

            -nbad -bap -bbo -nbc -br -brs -c33 -cd33 -ncdb -ce -ci4 -cli0
            -cp33 -cs -d0 -di1 -nfc1 -nfca -hnl -i4 -ip0 -l75 -lp -npcs
            -nprs -npsl -saf -sai -saw -nsc -nsob -nss

       Kernighan & Ritchie style does not put comments to the right of
       code in the same column at all times (nor does it use only one
       space to the right of the code), so for this style indent has
       arbitrarily chosen column 33.

       The style of the original Berkeley indent may be obtained by
       specifying ‘-orig’ (or by specifying ‘--original’, using the long
       option name).  This style is equivalent to the following
       settings:

            -nbad -nbap -bbo -bc -br -brs -c33 -cd33 -cdb -ce -ci4 -cli0
            -cp33 -di16 -fc1 -fca -hnl -i4 -ip4 -l75 -lp -npcs -nprs -psl
            -saf -sai -saw -sc -nsob -nss -ts8

       The Linux style is used in the linux kernel code and drivers.
       Code generally has to follow the Linux coding style to be
       accepted.  This style is equivalent to the following settings:

            -nbad -bap -nbc -bbo -hnl -br -brs -c33 -cd33 -ncdb -ce -ci4
            -cli0 -d0 -di1 -nfc1 -i8 -ip0 -l80 -lp -npcs -nprs -npsl -sai
            -saf -saw -ncs -nsc -sob -nfca -cp33 -ss -ts8 -il1

BLANK LINES         top

       Various programming styles use blank lines in different places.
       indent has a number of options to insert or delete blank lines in
       specific places.

       The ‘-bad’ option causes indent to force a blank line after every
       block of declarations.  The ‘-nbad’ option causes indent not to
       force such blank lines.

       The ‘-bap’ option forces a blank line after every procedure body.
       The ‘-nbap’ option forces no such blank line.

       The ‘-bbb’ option forces a blank line before every boxed comment
       (See COMMENTS.)  The ‘-nbbb’ option does not force such blank
       lines.

       The ‘-sob’ option causes indent to swallow optional blank lines
       (that is, any optional blank lines present in the input will be
       removed from the output).  If the ‘-nsob’ is specified, any blank
       lines present in the input file will be copied to the output
       file.

--blank-lines-after-declarations         top

       The ‘-bad’ option forces a blank line after every block of
       declarations.  The ‘-nbad’ option does not add any such blank
       lines.

       For example, given the input
            char *foo;
            char *bar;
            /* This separates blocks of declarations.  */
            int baz;

       indent -bad produces

            char *foo;
            char *bar;

            /* This separates blocks of declarations.  */
            int baz;

       and indent -nbad produces

            char *foo;
            char *bar;
            /* This separates blocks of declarations.  */
            int baz;

--blank-lines-after-procedures         top

       The ‘-bap’ option forces a blank line after every procedure body.

       For example, given the input

            int
            foo ()
            {
              puts("Hi");
            }
            /* The procedure bar is even less interesting.  */
            char *
            bar ()
            {
              puts("Hello");
            }

       indent -bap produces

            int
            foo ()
            {
              puts ("Hi");
            }

            /* The procedure bar is even less interesting.  */
            char *
            bar ()
            {
              puts ("Hello");
            }

       and indent -nbap produces

            int
            foo ()
            {
              puts ("Hi");
            }
            /* The procedure bar is even less interesting.  */
            char *
            bar ()
            {
              puts ("Hello");
            }

       No blank line will be added after the procedure foo.

COMMENTS         top

       indent formats both C and C++ comments. C comments are begun with
       ‘/*’, terminated with ‘*/’ and may contain newline characters.
       C++ comments begin with the delimiter ‘//’ and end at the
       newline.

       indent handles comments differently depending upon their context.
       indent attempts to distinguish between comments which follow
       statements, comments which follow declarations, comments
       following preprocessor directives, and comments which are not
       preceded by code of any sort, i.e., they begin the text of the
       line (although not necessarily in column 1).

       indent further distinguishes between comments found outside of
       procedures and aggregates, and those found within them.  In
       particular, comments beginning a line found within a procedure
       will be indented to the column at which code is currently
       indented.  The exception to this is a comment beginning in the
       leftmost column;  such a comment is output at that column.

       indent attempts to leave boxed comments unmodified. The general
       idea of such a comment is that it is enclosed in a rectangle or
       ‘‘box’’ of stars or dashes to visually set it apart.  More
       precisely, boxed comments are defined as those in which the
       initial ‘/*’ is followed immediately by the character ‘*’, ‘=’,
       ‘_’, or ‘-’, or those in which the beginning comment delimiter
       (‘/*’) is on a line by itself, and the following line begins with
       a ‘*’ in the same column as the star of the opening delimiter.

       Examples of boxed comments are:

            /**********************
             * Comment in a box!! *
             **********************/

                   /*
                    * A different kind of scent,
                    * for a different kind of comment.
                    */

       indent attempts to leave boxed comments exactly as they are found
       in the source file.  Thus the indentation of the comment is
       unchanged, and its length is not checked in any way.  The only
       alteration made is that an embedded tab character may be
       converted into the appropriate number of spaces.

       If the ‘-bbb’ option is specified, all such boxed comments will
       be preceded by a blank line, unless such a comment is preceded by
       code.

       Comments which are not boxed comments may be formatted, which
       means that the line is broken to fit within a right margin and
       left-filled with whitespace.  Single newlines are equivalent to a
       space, but blank lines (two or more newlines in a row) are taken
       to mean a paragraph break.  Formatting of comments which begin
       after the first column is enabled with the ‘-fca’ option.  To
       format those beginning in column one, specify ‘-fc1’.  Such
       formatting is disabled by default.

       The right margin for formatting defaults to 78, but may be
       changed with the ‘-lc’ option.  If the margin specified does not
       allow the comment to be printed, the margin will be automatically
       extended for the duration of that comment.  The margin is not
       respected if the comment is not being formatted.

       If the ‘-fnc’ option is specified, all comments with ‘/*’
       embedded will have that character sequence replaced by a space
       followed by the character ‘*’ thus eliminating nesting.

       If the comment begins a line (i.e., there is no program text to
       its left), it will be indented to the column it was found in
       unless the comment is within a block of code.  In that case, such
       a comment will be aligned with the indented code of that block
       (unless the comment began in the first column).  This alignment
       may be affected by the ‘-d’ option, which specifies an amount by
       which such comments are moved to the left, or unindented.  For
       example, ‘-d2’ places comments two spaces to the left of code.
       By default, comments are aligned with code, unless they begin in
       the first column, in which case they are left there by default
       --- to get them aligned with the code, specify ‘-fc1’.

       Comments to the right of code will appear by default in column
       33.  This may be changed with one of three options.  ‘-c’ will
       specify the column for comments following code, ‘-cd’ specifies
       the column for comments following declarations, and ‘-cp’
       specifies the column for comments following preprocessor
       directives #else and #endif. ‘-dj’ together with ‘-cd0’ can be
       used to suppress alignment of comments to the right of
       declarations, causing the comment to follow one tabstop from the
       end of the declaration. Normally ‘-cd0’ causes ‘-c’ to become
       effective.

       If the code to the left of the comment exceeds the beginning
       column, the comment column will be extended to the next tabstop
       column past the end of the code, or in the case of preprocessor
       directives, to one space past the end of the directive.  This
       extension lasts only for the output of that particular comment.

       The ‘-cdb’ option places the comment delimiters on blank lines.
       Thus, a single line comment like /* Loving hug */ can be
       transformed into:

            /*
               Loving hug
             */

       Stars can be placed at the beginning of multi-line comments with
       the ‘-sc’ option.  Thus, the single-line comment above can be
       transformed (with ‘-cdb -sc’) into:

            /*
             * Loving hug
             */

STATEMENTS         top

       The ‘-br’ or ‘-bl’ option specifies how to format braces.

       The ‘-br’ option formats statement braces like this:

            if (x > 0) {
              x--;
            }

       The ‘-bl’ option formats them like this:

            if (x > 0)
              {
                x--;
              }

       If you use the ‘-bl’ option, you may also want to specify the
       ‘-bli’ option.  This option specifies the number of spaces by
       which braces are indented.  ‘-bli2’, the default, gives the
       result shown above.  ‘-bli0’ results in the following:

            if (x > 0)
            {
              x--;
            }

       If you are using the ‘-br’ option, you probably want to also use
       the ‘-ce’ option.  This causes the else in an if-then-else
       construct to cuddle up to the immediately preceding ‘}’.  For
       example, with ‘-br -ce’ you get the following:

            if (x > 0) {
              x--;
            } else {
              fprintf (stderr, "...something wrong?\n");
            }

       With ‘-br -nce’ that code would appear as

            if (x > 0) {
              x--;
            }
            else {
              fprintf (stderr, "...something wrong?\n");
            }

       An exception to the behavior occurs when there is a comment
       between the right brace and the subsequent else statement.  While
       the ‘-br’ option will cause a left brace to jump over the
       comment, the else does not jump over the comment to cuddle
       because it has a strong likelihood of changing the meaning of the
       comment.

       The ‘-cdw’ option causes the while in a do-while loop to cuddle
       up to the immediately preceding ‘}’.  For example, with ‘-cdw’
       you get the following:

            do {
              x--;
            } while (x);

       With ‘-ncdw’ that code would appear as

            do {
              x--;
            }
            while (x);

       The ‘-cli’ option specifies the number of spaces that case labels
       should be indented to the right of the containing switch
       statement.

       The default gives code like:

            switch (i)
              {
              case 0:
                break;
              case 1:
                {
                  ++i;
                }
              default:
                break;
              }

       Using the ‘-cli2’ that would become:

            switch (i)
              {
                case 0:
                  break;
                case 1:
                  {
                    ++i;
                  }
                default:
                  break;
              }

       The indentation of the braces below a case statement can be
       controlled with the ‘-cbin’ option.  For example, using ‘-cli2
       -cbi0’ results in:

            switch (i)
              {
                case 0:
                  break;
                case 1:
                {
                  ++i;
                }
                default:
                  break;
              }

       If a semicolon is on the same line as a for or while statement,
       the ‘-ss’ option will cause a space to be placed before the
       semicolon.  This emphasizes the semicolon, making it clear that
       the body of the for or while statement is an empty statement.
       ‘-nss’ disables this feature.

       The ‘-pcs’ option causes a space to be placed between the name of
       the procedure being called and the ‘(’ (for example,
       puts ("Hi");.  The ‘-npcs’ option would give puts("Hi");).

       If the ‘-cs’ option is specified, indent puts a space between a
       cast operator and the object to be cast. The ‘-ncs’ ensures that
       there is no space between the cast operator and the object.
       Remember that indent only knows about the standard C data types
       and so cannot recognise user-defined types in casts. Thus
       (mytype)thing is not treated as a cast.

       The ‘-bs’ option ensures that there is a space between the
       keyword sizeof and its argument.  In some versions, this is known
       as the ‘Bill_Shannon’ option.

       The ‘-saf’ option forces a space between a for and the following
       parenthesis.  This is the default.

       The ‘-sai’ option forces a space between a if and the following
       parenthesis.  This is the default.

       The ‘-saw’ option forces a space between a while and the
       following parenthesis.  This is the default.

       The ‘-prs’ option causes all parentheses to be separated with a
       space from whatever is between them.  For example, using ‘-prs’
       results in code like:

              while ( ( e_code - s_code ) < ( dec_ind - 1 ) )
                {
                  set_buf_break ( bb_dec_ind );
                  *e_code++ = ’ ’;
                }

DECLARATIONS         top

       By default indent will line up identifiers, in the column
       specified by the ‘-di’ option.  For example, ‘-di16’ makes things
       look like:

            int             foo;
            char           *bar;

       Using a small value (such as one or two) for the ‘-di’ option can
       be used to cause the identifiers to be placed in the first
       available position; for example:

            int foo;
            char *bar;

       The value given to the ‘-di’ option will still affect variables
       which are put on separate lines from their types, for example
       ‘-di2’ will lead to:

            int
              foo;

       If the ‘-bc’ option is specified, a newline is forced after each
       comma in a declaration.  For example,

            int a,
              b,
              c;

       With the ‘-nbc’ option this would look like

            int a, b, c;

       The ‘-bfda’ option causes a newline to be forced after the comma
       separating the arguments of a function declaration.  The
       arguments will appear at one indention level deeper than the
       function declaration.  This is particularly helpful for functions
       with long argument lists.  The option ‘-bfde’ causes a newline to
       be forced before the closing bracket of the function declaration.
       For both options the ’n’ setting is the default: -nbdfa and
       -nbdfe.

       For example,

            void foo (int arg1, char arg2, int *arg3, long arg4, char arg5);
       With the ‘-bfda’ option this would look like

            void foo (
                int arg1,
                char arg2,
                int *arg3,
                long arg4,
                char arg5);

       With, in addition, the ‘-bfde’ option this would look like

            void foo (
                int arg1,
                char arg2,
                int *arg3,
                long arg4,
                char arg5
                );

       The ‘-psl’ option causes the type of a procedure being defined to
       be placed on the line before the name of the procedure.  This
       style is required for the etags program to work correctly, as
       well as some of the c-mode functions of Emacs.

       You must use the ‘-T’ option to tell indent the name of all the
       typenames in your program that are defined by typedef.  ‘-T’ can
       be specified more than once, and all names specified are used.
       For example, if your program contains

            typedef unsigned long CODE_ADDR;
            typedef enum {red, blue, green} COLOR;

       you would use the options ‘-T CODE_ADDR -T COLOR’.

       The ‘-brs’ or ‘-bls’ option specifies how to format braces in
       struct declarations.  The ‘-brs’ option formats braces like this:

            struct foo {
              int x;
            };

       The ‘-bls’ option formats them like this:

            struct foo
            {
              int x;
            };

       Similarly to the structure brace ‘-brs’ and ‘-bls’ options,
        the function brace options ‘-brf’ or ‘-blf’ specify how to
       format the braces in function definitions.  The ‘-brf’ option
       formats braces like this:

            int one(void) {
              return 1;
            };

       The ‘-blf’ option formats them like this:

            int one(void)
            {
              return 1;
            };

INDENTATION         top

       One issue in the formatting of code is how far each line should
       be indented from the left margin.  When the beginning of a
       statement such as if or for is encountered, the indentation level
       is increased by the value specified by the ‘-i’ option.  For
       example, use ‘-i8’ to specify an eight character indentation for
       each level.  When a statement is broken across two lines, the
       second line is indented by a number of additional spaces
       specified by the ‘-ci’ option.  ‘-ci’ defaults to 0.  However, if
       the ‘-lp’ option is specified, and a line has a left parenthesis
       which is not closed on that line, then continuation lines will be
       lined up to start at the character position just after the left
       parenthesis.  This processing also applies to ‘[’ and applies to
       ‘{’ when it occurs in initialization lists.  For example, a piece
       of continued code might look like this with ‘-nlp -ci3’ in
       effect:

              p1 = first_procedure (second_procedure (p2, p3),
                 third_procedure (p4, p5));

       With ‘-lp’ in effect the code looks somewhat clearer:

              p1 = first_procedure (second_procedure (p2, p3),
                                    third_procedure (p4, p5));

       When a statement is broken in between two or more paren pairs
       (...), each extra pair causes the indentation level extra
       indentation:

            if ((((i < 2 &&
                    k > 0) || p == 0) &&
                q == 1) ||
              n = 0)

       The option ‘-ipN’ can be used to set the extra offset per paren.
       For instance, ‘-ip0’ would format the above as:

            if ((((i < 2 &&
              k > 0) || p == 0) &&
              q == 1) ||
              n = 0)

       indent assumes that tabs are placed at regular intervals of both
       input and output character streams.  These intervals are by
       default 8 columns wide, but (as of version 1.2) may be changed by
       the ‘-ts’ option.  Tabs are treated as the equivalent number of
       spaces.

       The indentation of type declarations in old-style function
       definitions is controlled by the ‘-ip’ parameter.  This is a
       numeric parameter specifying how many spaces to indent type
       declarations.  For example, the default ‘-ip5’ makes definitions
       look like this:

            char *
            create_world (x, y, scale)
                 int x;
                 int y;
                 float scale;
            {
              . . .
            }

       For compatibility with other versions of indent, the option
       ‘-nip’ is provided, which is equivalent to ‘-ip0’.

       ANSI C allows white space to be placed on preprocessor command
       lines between the character ‘#’ and the command name.  By
       default, indent removes this space, but specifying the ‘-lps’
       option directs indent to leave this space unmodified. The option
       ‘-ppi’ overrides  ‘-nlps’ and  ‘-lps’.

       This option can be used to request that preprocessor conditional
       statements can be indented by to given number of spaces, for
       example with the option ‘-ppi 3’

            #if X
            #if Y
            #define Z 1
            #else
            #define Z 0
            #endif
            #endif
       becomes
            #if X
            #   if Y
            #      define Z 1
            #   else
            #      define Z 0
            #   endif
            #endif

       This option sets the offset at which a label (except case labels)
       will be positioned. If it is set to zero or a positive number,
       this indicates how far from the left margin to indent a label.
       If it is set to a negative number, this indicates how far back
       from the current indent level to place the label.  The default
       setting is -2 which matches the behaviour of earlier versions of
       indent.  Note that this parameter does not affect the placing of
       case labels; see the ‘-cli’ parameter for that. For example with
       the option ‘-il 1’

            group
            function()
            {
                if (do_stuff1() == ERROR)
                    goto cleanup1;

                if (do_stuff2() == ERROR)
                    goto cleanup2;

                return SUCCESS;

              cleanup2:
                do_cleanup2();

              cleanup1:
                do_cleanup1();

                return ERROR;
            }
       becomes
            group
            function()
            {
                if (do_stuff1() == ERROR)
                    goto cleanup1;

                if (do_stuff2() == ERROR)
                    goto cleanup2;

                return SUCCESS;

             cleanup2:
                do_cleanup2();

             cleanup1:
                do_cleanup1();

                return ERROR;
            }

BREAKING LONG LINES         top

       With the option ‘-ln’, or ‘--line-lengthn’, it is possible to
       specify the maximum length of a line of C code, not including
       possible comments that follow it.

       When lines become longer than the specified line length, GNU
       indent tries to break the line at a logical place.  This is new
       as of version 2.1 however and not very intelligent or flexible
       yet.

       Currently there are three options that allow one to interfere
       with the algorithm that determines where to break a line.

       The ‘-bbo’ option causes GNU indent to prefer to break long lines
       before the boolean operators && and ||.  The ‘-nbbo’ option
       causes GNU indent not have that preference.  For example, the
       default option ‘-bbo’ (together with ‘--line-length60’ and
       ‘--ignore-newlines’) makes code look like this:

              if (mask
                  && ((mask[0] == ’\0’)
                      || (mask[1] == ’\0’
                          && ((mask[0] == ’0’) || (mask[0] == ’*’)))))

       Using the option ‘-nbbo’ will make it look like this:

              if (mask &&
                  ((mask[0] == ’\0’) ||
                   (mask[1] == ’\0’ &&
                    ((mask[0] == ’0’) || (mask[0] == ’*’)))))

       The default ‘-hnl’, however, honours newlines in the input file
       by giving them the highest possible priority to break lines at.
       For example, when the input file looks like this:

              if (mask
                  && ((mask[0] == ’\0’)
                  || (mask[1] == ’\0’ && ((mask[0] == ’0’) || (mask[0] == ’*’)))))

       then using the option ‘-hnl’, or ‘--honour-newlines’, together
       with the previously mentioned ‘-nbbo’ and ‘--line-length60’, will
       cause the output not to be what is given in the last example but
       instead will prefer to break at the positions where the code was
       broken in the input file:

              if (mask
                  && ((mask[0] == ’\0’)
                      || (mask[1] == ’\0’ &&
                          ((mask[0] == ’0’) || (mask[0] == ’*’)))))

       The idea behind this option is that lines which are too long, but
       are already broken up, will not be touched by GNU indent.  Really
       messy code should be run through indent at least once using the
       ‘--ignore-newlines’ option though.

       The ‘-gts’ option affects how the gettext standard macros _() and
       N_() are treated.  The default behavior (or the use of ‘-ngts’)
       causes indent to treat them as it does other functions, so that a
       long string is broken like the following example.

              if (mask)
                {
                  warning (_
                           ("This is a long string that stays together."));
                }

       With the ‘-gts’ option, the underscore is treated as a part of
       the string, keeping it tied to the string, and respecting the
       fact that gettext is unobtrusively providing a localized string.
       This only works if _(" is together as a unit at the beginning of
       the string and ") is together as a unit at the end.

              if (mask)
                {
                  warning
                    (_("This is a long string that stays together."));
                }

DISABLING FORMATTING         top

       Formatting of C code may be disabled for portions of a program by
       embedding special control comments in the program.  To turn off
       formatting for a section of a program, place the disabling
       control comment /* *INDENT-OFF* */ on a line by itself just
       before that section.  Program text scanned after this control
       comment is output precisely as input with no modifications until
       the corresponding enabling comment is scanned on a line by
       itself.  The disabling control comment is /* *INDENT-ON* */, and
       any text following the comment on the line is also output
       unformatted.  Formatting begins again with the input line
       following the enabling control comment.

       More precisely, indent does not attempt to verify the closing
       delimiter (*/) for these C comments, and any whitespace on the
       line is totally transparent.

       These control comments also function in their C++ formats, namely
       // *INDENT-OFF* and // *INDENT-ON*.

       It should be noted that the internal state of indent remains
       unchanged over the course of the unformatted section.  Thus, for
       example, turning off formatting in the middle of a function and
       continuing it after the end of the function may lead to bizarre
       results.  It is therefore wise to be somewhat modular in
       selecting code to be left unformatted.

       As a historical note, some earlier versions of indent produced
       error messages beginning with *INDENT**.  These versions of
       indent were written to ignore any input text lines which began
       with such error messages.  I have removed this incestuous feature
       from GNU indent.

MISCELLANEOUS OPTIONS         top

       To find out what version of indent you have, use the command
       indent -version. This will report the version number of indent,
       without doing any of the normal processing.

       The ‘-v’ option can be used to turn on verbose mode.  When in
       verbose mode, indent reports when it splits one line of input
       into two more more lines of output, and gives some size
       statistics at completion.

       The ‘-pmt’ option causes indent to preserve the access and
       modification times on the output files.  Using this option has
       the advantage that running indent on all source and header files
       in a project won’t cause make to rebuild all targets.  This
       option is only available on Operating Systems that have the POSIX
       utime(2) function.

BUGS         top

       Please report any bugs to bug-indent@gnu.org.

       When indent is run twice on a file, with the same profile, it
       should never change that file the second time.  With the current
       design of indent, this can not be guaranteed, and it has not been
       extensively tested.

       indent does not understand C. In some cases this leads to the
       inability to join lines.  The result is that running a file
       through indent is irreversible, even if the used input file was
       the result of running indent with a given profile
       (‘.indent.pro’).

       While an attempt was made to get indent working for C++, it will
       not do a good job on any C++ source except the very simplest.

       indent does not look at the given ‘--line-length’ option when
       writing comments to the output file.  This results often in
       comments being put far to the right.  In order to prohibit indent
       from joining a broken line that has a comment at the end, make
       sure that the comments start on the first line of the break.

       indent does not count lines and comments (see the ‘-v’ option)
       when indent is turned off with /* *INDENT-OFF* */.

       Comments of the form /*UPPERCASE*/ are not treated as comment but
       as an identifier, causing them to be joined with the next line.
       This renders comments of this type useless, unless they are
       embedded in the code to begin with.

COPYRIGHT         top

       The following copyright notice applies to the indent program.
       The copyright and copying permissions for this manual appear near
       the beginning of ‘indent.texinfo’ and ‘indent.info’, and near the
       end of ‘indent.1’.

       Copyright (c) 2001 David Ingamells.
       Copyright (c) 1999 Carlo Wood.
       Copyright (c) 1995, 1996 Joseph Arceneaux.
       Copyright (c) 1989, 1992, 1993, 1994, 1995, 1996, 2014 Free Software Foundation
       Copyright (c) 1985 Sun Microsystems, Inc.
       Copyright (c) 1980 The Regents of the University of California.
       Copyright (c) 1976 Board of Trustees of the University of Illinois.
       All rights reserved.

       Redistribution and use in source and binary forms are permitted
       provided that the above copyright notice and this paragraph are
       duplicated in all such forms and that any documentation,
       advertising materials, and other materials related to such
       distribution and use acknowledge that the software was developed
       by the University of California, Berkeley, the University of Illinois,
       Urbana, and Sun Microsystems, Inc.  The name of either University
       or Sun Microsystems may not be used to endorse or promote products
       derived from this software without specific prior written permission.
       THIS SOFTWARE IS PROVIDED ‘‘AS IS’’ AND WITHOUT ANY EXPRESS OR
       IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
       WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
       PURPOSE.

Options’ Cross Key         top

       Here is a list of options alphabetized by long option, to help
       you find the corresponding short option.

            --blank-lines-after-commas                      -bc
            --blank-lines-after-declarations                -bad
            --blank-lines-after-procedures                  -bap
            --blank-lines-before-block-comments             -bbb
            --braces-after-if-line                          -bl
            --braces-after-func-def-line                    -blf
            --brace-indent                                  -bli
            --braces-after-struct-decl-line                 -bls
            --braces-on-if-line                             -br
            --braces-on-func-def-line                       -brf
            --braces-on-struct-decl-line                    -brs
            --break-after-boolean-operator                  -nbbo
            --break-before-boolean-operator                 -bbo
            --break-function-decl-args                      -bfda
            --break-function-decl-args-end                  -bfde
            --case-indentation                              -clin
            --case-brace-indentation                        -cbin
            --comment-delimiters-on-blank-lines             -cdb
            --comment-indentation                           -cn
            --continuation-indentation                      -cin
            --continue-at-parentheses                       -lp
            --cuddle-do-while                               -cdw
            --cuddle-else                                   -ce
            --declaration-comment-column                    -cdn
            --declaration-indentation                       -din
            --dont-break-function-decl-args                 -nbfda
            --dont-break-function-decl-args-end             -nbfde
            --dont-break-procedure-type                     -npsl
            --dont-cuddle-do-while                          -ncdw
            --dont-cuddle-else                              -nce
            --dont-format-comments                          -nfca
            --dont-format-first-column-comments             -nfc1
            --dont-line-up-parentheses                      -nlp
            --dont-left-justify-declarations                -ndj
            --dont-space-special-semicolon                  -nss
            --dont-star-comments                            -nsc
            --else-endif-column                             -cpn
            --format-all-comments                           -fca
            --format-first-column-comments                  -fc1
            --gnu-style                                     -gnu
            --honour-newlines                               -hnl
            --ignore-newlines                               -nhnl
            --ignore-profile                                -npro
            --indent-label                                  -iln
            --indent-level                                  -in
            --k-and-r-style                                 -kr
            --leave-optional-blank-lines                    -nsob
            --leave-preprocessor-space                      -lps
            --left-justify-declarations                     -dj
            --line-comments-indentation                     -dn
            --line-length                                   -ln
            --linux-style                                   -linux
            --no-blank-lines-after-commas                   -nbc
            --no-blank-lines-after-declarations             -nbad
            --no-blank-lines-after-procedures               -nbap
            --no-blank-lines-before-block-comments          -nbbb
            --no-comment-delimiters-on-blank-lines          -ncdb
            --no-space-after-casts                          -ncs
            --no-parameter-indentation                      -nip
            --no-space-after-for                    -nsaf
            --no-space-after-function-call-names            -npcs
            --no-space-after-if                -nsai
            --no-space-after-parentheses                    -nprs
            --no-space-after-while                  -nsaw
            --no-tabs                                       -nut
            --no-verbosity                                  -nv
            --original                                      -orig
            --parameter-indentation                         -ipn
            --paren-indentation                             -pin
            --preserve-mtime                   -pmt
            --preprocessor-indentation                      -ppin
            --procnames-start-lines                         -psl
            --space-after-cast                              -cs
            --space-after-for                  -saf
            --space-after-if                   -sai
            --space-after-parentheses                       -prs
            --space-after-procedure-calls                   -pcs
            --space-after-while                -saw
            --space-special-semicolon                       -ss
            --standard-output                               -st
            --start-left-side-of-comments                   -sc
            --struct-brace-indentation                      -sbin
            --swallow-optional-blank-lines                  -sob
            --tab-size                                      -tsn
            --use-tabs                                      -ut
            --verbose                                       -v

RETURN VALUE         top

       Unknown

FILES         top

       $HOME/.indent.pro   holds default options for indent.

AUTHORS         top

       Carlo Wood
       Joseph Arceneaux
       Jim Kingdon
       David Ingamells

HISTORY         top

       Derived from the UCB program "indent".

COPYING         top

       Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 2014 Free
       Software Foundation, Inc.  Copyright (C) 1995, 1996 Joseph
       Arceneaux.  Copyright (C) 1999 Carlo Wood.  Copyright (C) 2001
       David Ingamells.  Copyright (C) 2013 Łukasz Stelmach.

       Permission is granted to make and distribute verbatim copies of
       this manual provided the copyright notice and this permission
       notice are preserved on all copies.

COLOPHON         top

       This page is part of the GNU indent (a C program formatter)
       project.  Information about the project can be found at 
       ⟨http://www.gnu.org/software/indent/⟩.  If you have a bug report
       for this manual page, send it to bug-indent@gnu.org.  This page
       was obtained from the project's upstream Mercurial repository
       ⟨http://hg.savannah.gnu.org/hgweb/indent/⟩ on 2021-04-01.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2018-09-06.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

                                                              INDENT(1L)