DELTA(P) POSIX Programmer's Manual DELTA(P)NAMEdelta - make a delta (change) to an SCCS file (DEVELOPMENT)
SYNOPSISdelta [-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 associ‐
ated with each file. See the STDOUT section.
-n Specify retention of the edited g-file (normally removed at com‐
pletion 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 sec‐
tion 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 pro‐
gram 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 (speci‐
fied as either -y, -y "" , or in response to a prompt for a com‐
ment) 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 Vari‐
ables 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 unspeci‐
fied 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 speci‐
fied) 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 unspeci‐
fied.
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 .
IEEE/The Open Group 2003 DELTA(P)
