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.1‐2008, 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 delta.

       −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

                 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 <backslash>.

                 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

                 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 <backslash>.

                 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

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

        *  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 delta.


       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.1‐2008, Section 8.2, Internationalization
                 Variables for the precedence of internationalization
                 variables used to determine the values of locale

       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

                 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 used.


       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

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

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 body.

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.1‐2008, 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, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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                 2013                           DELTA(1P)