Man Linux: Main Page and Category List

NAME

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

SYNOPSIS

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

DESCRIPTION

       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

       The  delta  utility  shall  conform  to  the Base Definitions volume of
       IEEE Std 1003.1-2001, 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 .

       -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 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 .

       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>s or escaped <newline>s.  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 valid.)

       -y[comment]
              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 diff .

OPERANDS

       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

       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

       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.

ENVIRONMENT VARIABLES

       The  following  environment  variables  shall  affect  the execution of
       delta:

       LANG   Provide a default value for the  internationalization  variables
              that  are  unset  or  null.  (See the Base Definitions volume of
              IEEE Std 1003.1-2001,    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).

       LC_MESSAGES
              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.

ASYNCHRONOUS EVENTS

       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 Utility Description Defaults .

STDOUT

       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 prompt.

        * 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

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES

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

EXTENDED DESCRIPTION

   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

       The following exit values shall be returned:

        0     Successful completion.

       >0     An error occurred.

CONSEQUENCES OF ERRORS

       Default.

       The following sections are informative.

APPLICATION USAGE

       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

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       Utility Description Defaults , admin , diff , get , prs , rmdel

COPYRIGHT

       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications  Issue  6,  Copyright  (C) 2001-2003 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 http://www.opengroup.org/unix/online.html .