delta(1) General Commands Manual delta(1)
NAME
delta - Saves editing changes in a Source Code Control System (SCCS) file
SYNOPSIS
delta [-g list] [-m MRlist] [-n] [-p] [-s] [-r SID] [-y [comment]] file... | -
STANDARDS
Interfaces documented on this reference page conform to industry standards as follows:
delta: XPG4, XPG4-UNIX
Refer to the standards(5) reference page for more information about industry standards and associated tags.
OPTIONS
Specifies a list of SIDs (deltas) that are to be ignored when the get command creates the g-file. After you use this option, get ignores
the deltas in this list when it builds the g-file. Specifies a Modification Request (MR) number as the reason for creating the new delta.
If the SCCS file has the v header flag set, then a MR number must be provided. If you specify -m, the MRs are taken from MRlist.
If you do not specify the -m option, delta reads MRs from the standard input. If standard input is a terminal, delta prompts you
for the MRs. The delta command continues to take input until it reads End-of-File or an unescaped newline character. It always
reads MRs before the comments (see the -y option). You can use spaces, tab characters, or both to separate MRs in a list.
If the v header flag has a value, it is interpreted as the name of a program that validates the MR numbers. If delta returns a
nonzero exit value from the MR validation program, delta assumes some of the MR numbers were invalid and stops running. Retains the
g-file, which is normally removed at completion of delta processing. Writes to standard output (in the format of the sccsdiff com-
mand) the SCCS file differences before and after the delta is applied. (See the sccsdiff(1) reference page for more information.)
Specifies which delta is to be made to the SCCS file. You must use this option only if two or more outstanding get -e commands were
done on the same SCCS file by the same person. The SID can be either the SID specified on the get command line or the SID to be
made as reported by the get command. An error results if the specified SID cannot be uniquely identified, or if a SID must be spec-
ified, but it is not. Suppresses the information normally written to standard output on normal completion of the delta command.
Specifies text used to describe the reason for making the delta. A null string is considered a valid comment. If your comment line
includes special characters or spaces, the line must be enclosed in single or double quotes.
If you do not specify -y, delta reads comments from standard input until it reads a blank line or End-of-File. If input is from the
keyboard, delta prompts for the comments. If the last character of a line is a (backslash), it is ignored. Comments must be no
longer than 512 characters.
OPERANDS
The path name of an existing SCCS file or directory.
If you specify a directory in place of file, delta performs the requested actions on all SCCS files within that directory (that is,
on all files with the s. prefix).
If you specify a - (dash) in place of file, delta reads standard input and interprets each line as the name of an SCCS file. When
delta reads standard input, you must supply the -y option. You must also supply the -m option if the v header flag is set. (For
more information on header flags, see the admin(1) reference page.) The delta command reads standard input until it reaches End-of-
File.
DESCRIPTION
The delta command reads the g-files that correspond to the specified files (see the get(1) reference page) and creates a new delta.
The delta command introduces into the named SCCS file any changes that were made to the file version retrieved by an SCCS get -e command.
[Tru64 UNIX] Avoid a get of many SCCS files followed by a delta of those files when the get generates a large amount of data. Instead,
alternate the use of get and delta.
To use the delta command, do the following: Use get -e to get an editable version of the file. Edit that file. Use delta to create a new
version of the SCCS file.
[Tru64 UNIX] The delta command prompts you for comments. The comments are for that particular delta and appear in the SCCS file header.
The comments are not retrieved when you get the delta and do not appear in the text of a retrieved file. Use comments to keep track of why
a delta was created.
[Tru64 UNIX] To see the comments, use an editor to look at the SCCS file, write the SCCS file to the display screen with the cat command,
or print selected parts of the file to standard output using the prs command. Remember not to change the contents of the SCCS file
directly. To change the delta comments, use the cdc(1) command.
[Tru64 UNIX] SCCS does not allow use of the delta command if an editable file does not exist. However, once an editable file exists (cre-
ated with get -e), SCCS creates the delta without checking the data being stored in the file.
Do not use the delta command on a file if it contains expanded identification keywords. Read-only file versions replace keywords with text
values. Using delta on a read-only file causes the keywords to be lost. If this happens, remove the delta with the rmdel command or reedit
the file and replace the identification keywords. SCCS does not allow you to use delta unless an editable copy of the file exists.
To prevent the loss of keywords, use the admin command with the -f option to specify the i option.
NOTES
Lines beginning with an SOH ASCII character (binary 001) cannot be placed in the SCCS file unless the SOH character is quoted using a
(backslash). The SOH has special meaning to SCCS and causes an error. See the sccsfile(4) reference page.
EXIT STATUS
The following exit values are returned: Successful completion. An error occurred.
EXAMPLES
To record changes you have made to an SCCS file, enter: delta s.prog.c
This adds a delta to the SCCS file s.prog.c, recording the changes made by editing prog.c. The delta command then asks you for a
comment that summarizes the changes you made. Enter the comment, then press the End-of-File key sequence or press <Return> twice to
indicate that you have finished the comment. To record changes to an SCCS file and specify the comment for the delta on the command
line, enter: delta s.prog.c -y "Updated calendar function for 1993."
ENVIRONMENT VARIABLES
The following environment variables affect the execution of delta: Provides a default value for the internationalization variables that are
unset or null. If LANG is unset or null, the corresponding value from the default locale is used. If any of the internationalization vari-
ables contain an invalid setting, the utility behaves as if none of the variables had been defined. If set to a non-empty string value,
overrides the values of all the other internationalization variables. Determines the locale for the interpretation of sequences of bytes
of text data as characters (for example, single-byte as opposed to multibyte characters in arguments and input files). Determines the
locale for the format and contents of diagnostic messages written to standard error. Determines the location of message catalogues for the
processing of LC_MESSAGES.
SEE ALSO
Commands: admin(1), bdiff(1), cdc(1), comb(1), get(1), prs(1), rmdel(1), sact(1), sccs(1), sccsdiff(1), sccshelp(1), unget(1), val(1),
what(1)
Files: sccsfile(4)
Standards: standards(5)
Programming Support Tools
delta(1)