delta - Saves editing changes in a Source Code Control System (SCCS) file
delta [-g list] [-m MRlist] [-n] [-p] [-s] [-r SID] [-y [comment]] file...
Interfaces documented on this reference page conform to industry standards
delta: XPG4, XPG4-UNIX
Refer to the standards(5) reference page for more information about indus-
try standards and associated tags.
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 com-
ments (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.
-n Retains the g-file, which is normally removed at completion of delta
-p Writes to standard output (in the format of the sccsdiff command) 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 specified, but it is not.
-s Suppresses the information normally written to standard output on nor-
mal 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
If you do not specify -y, delta reads comments from the standard input.
If the last character of a line is a \ (backslash), it prompts for
further comments. This way, comments could be entered as many lines
till 512 characters. (This \ is not included in the comment). The com-
ment terminates when it encounters a newline or End-of-File.
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.
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:
1. Use get -e to get an editable version of the file.
2. Edit that file.
3. 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 (created with
get -e), SCCS creates the delta without checking the data being stored in
Do not use the delta command on a file if it contains expanded identifica-
tion 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.
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.
The following exit values are returned:
0 Successful completion.
>>0 An error occurred.
1. To record changes you have made to an SCCS file, enter:
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.
2. 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."
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
variables 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 multi-
byte 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
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)
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