delta(1p) — Linux manual page


DELTA(1P)               POSIX Programmer's Manual              DELTA(1P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.

NAME         top

       delta — make a delta (change) to an SCCS file (DEVELOPMENT)

SYNOPSIS         top

       delta [-nps] [-g list] [-m mrlist] [-r SID] [-y[comment]] file...

DESCRIPTION         top

       The delta utility shall be used to permanently introduce into the
       named SCCS files changes that were made to the files retrieved by
       get (called the g-files, or generated files).

OPTIONS         top

       The delta utility shall conform to the Base Definitions volume of
       POSIX.1‐2017, Section 12.2, Utility Syntax Guidelines, except
       that the -y option has an optional option-argument. This optional
       option-argument shall not be presented as a separate argument.

       The following options shall be supported:

       -r SID    Uniquely identify which delta is to be made to the SCCS
                 file. The use of this option shall be necessary only if
                 two or more outstanding get commands for editing (get
                 -e) on the same SCCS file were done by the same person
                 (login name). The SID value specified with the -r
                 option can be either the SID specified on the get
                 command line or the SID to be made as reported by the
                 get utility; see get(1p).

       -s        Suppress the report to standard output of the activity
                 associated with each file.  See the STDOUT section.

       -n        Specify retention of the edited g-file (normally
                 removed at completion of delta processing).

       -g list   Specify a list (see get(1p) for the definition of list)
                 of deltas that shall be ignored when the file is
                 accessed at the change level (SID) created by this

       -m mrlist Specify a modification request (MR) number that the
                 application shall supply as the reason for creating the
                 new delta. This shall be used if the SCCS file has the
                 v flag set; see admin(1p).

                 If -m is not used and '-' is not specified as a file
                 argument, and the standard input is a terminal, the
                 prompt described in the STDOUT section shall be written
                 to standard output before the standard input is read;
                 if the standard input is not a terminal, no prompt
                 shall be issued.

                 MRs in a list shall be separated by <blank> characters
                 or escaped <newline> characters. An unescaped <newline>
                 shall terminate the MR list. The escape character is

                 If the v flag has a value, it shall be taken to be the
                 name of a program which validates the correctness of
                 the MR numbers. If a non-zero exit status is returned
                 from the MR number validation program, the delta
                 utility shall terminate. (It is assumed that the MR
                 numbers were not all valid.)

                 Describe the reason for making the delta. The comment
                 shall be an arbitrary group of lines that would meet
                 the definition of a text file. Implementations shall
                 support comments from zero to 512 bytes and may support
                 longer values. A null string (specified as either -y,
                 -y"", or in response to a prompt for a comment) shall
                 be considered a valid comment.

                 If -y is not specified and '-' is not specified as a
                 file argument, and the standard input is a terminal,
                 the prompt described in the STDOUT section shall be
                 written to standard output before the standard input is
                 read; if the standard input is not a terminal, no
                 prompt shall be issued. An unescaped <newline> shall
                 terminate the comment text. The escape character is

                 The -y option shall be required if the file operand is
                 specified as '-'.

       -p        Write (to standard output) the SCCS file differences
                 before and after the delta is applied in diff format;
                 see diff(1p).

OPERANDS         top

       The following operand shall be supported:

       file      A pathname of an existing SCCS file or a directory. If
                 file is a directory, the delta utility shall behave as
                 though each file in the directory were specified as a
                 named file, except that non-SCCS files (last component
                 of the pathname does not begin with s.)  and unreadable
                 files shall be silently ignored.

                 If exactly one file operand appears, and it is '-', the
                 standard input shall be read; each line of the standard
                 input shall be taken to be the name of an SCCS file to
                 be processed. Non-SCCS files and unreadable files shall
                 be silently ignored.

STDIN         top

       The standard input shall be a text file used only in the
       following cases:

        *  To read an mrlist or a comment (see the -m and -y options).

        *  A file operand shall be specified as '-'.  In this case, the
           -y option must be used to specify the comment, and if the
           SCCS file has the v flag set, the -m option must also be used
           to specify the MR list.

INPUT FILES         top

       Input files shall be text files whose data is to be included in
       the SCCS files. If the first character of any line of an input
       file is <SOH> in the POSIX locale, the results are unspecified.
       If this file contains more than 99999 lines, the number of lines
       recorded in the header for this file shall be 99999 for this


       The following environment variables shall affect the execution of

       LANG      Provide a default value for the internationalization
                 variables that are unset or null. (See the Base
                 Definitions volume of POSIX.1‐2017, Section 8.2,
                 Internationalization Variables for the precedence of
                 internationalization variables used to determine the
                 values of locale categories.)

       LC_ALL    If set to a non-empty string value, override the values
                 of all the other internationalization variables.

       LC_CTYPE  Determine the locale for the interpretation of
                 sequences of bytes of text data as characters (for
                 example, single-byte as opposed to multi-byte
                 characters in arguments and input files).

                 Determine the locale that should be used to affect the
                 format and contents of diagnostic messages written to
                 standard error, and informative messages written to
                 standard output.

       NLSPATH   Determine the location of message catalogs for the
                 processing of LC_MESSAGES.

       TZ        Determine the timezone in which the time and date are
                 written in the SCCS file. If the TZ variable is unset
                 or NULL, an unspecified system default timezone is


       If SIGINT is caught, temporary files shall be cleaned up and
       delta shall exit with a non-zero exit code. The standard action
       shall be taken for all other signals; see Section 1.4, Utility
       Description Defaults.

STDOUT         top

       The standard output shall be used only for the following messages
       in the POSIX locale:

        *  Prompts (see the -m and -y options) in the following formats:

               "MRs? "

               "comments? "

           The MR prompt, if written, shall always precede the comments

        *  A report of each file's activities (unless the -s option is
           specified) in the following format:

               "%s\n%d inserted\n%d deleted\n%d unchanged\n", <New SID>,
                   <number of lines inserted>, <number of lines deleted>,
                   <number of lines unchanged>

STDERR         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top

       Any SCCS files updated shall be files of an unspecified format.


   System Date and Time
       When a delta is added to an SCCS file, the system date and time
       shall be recorded for the new delta. If a get is performed using
       an SCCS file with a date recorded apparently in the future, the
       behavior is unspecified.

EXIT STATUS         top

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.



       The following sections are informative.


       Problems can arise if the system date and time have been modified
       (for example, put forward and then back again, or unsynchronized
       clocks across a network) and can also arise when different values
       of the TZ environment variable are used.

       Problems of a similar nature can also arise for the operation of
       the get utility, which records the date and time in the file

EXAMPLES         top


RATIONALE         top




SEE ALSO         top

       Section 1.4, Utility Description Defaults, admin(1p), diff(1p),
       get(1p), prs(1p), rmdel(1p)

       The Base Definitions volume of POSIX.1‐2017, Chapter 8,
       Environment Variables, Section 12.2, Utility Syntax Guidelines

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  In the event of any
       discrepancy between this version and the original IEEE and The
       Open Group Standard, the original IEEE and The Open Group
       Standard is the referee document. The original Standard can be
       obtained online at .

       Any typographical or formatting errors that appear in this page
       are most likely to have been introduced during the conversion of
       the source files to man page format. To report such errors, see .

IEEE/The Open Group               2017                         DELTA(1P)

Pages that refer to this page: admin(1p)get(1p)prs(1p)rmdel(1p)sact(1p)sccs(1p)unget(1p)val(1p)