delta(1)delta(1)NAMEdelta - Saves editing changes in a Source Code Control System (SCCS)
file
SYNOPSISdelta [-g list] [-m MRlist] [-n] [-p] [-s] [-r SID] [-y [comment]]
file... | -
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards 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 Modifica‐
tion 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 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 per‐
son. 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 identi‐
fied, or if a SID must be specified, 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 con‐
sidered 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 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 comment terminates when it encoun‐
ters a newline or End-of-File.
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) refer‐
ence 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
(created 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 identi‐
fication 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: Pro‐
vides 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, over‐
rides 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 process‐
ing 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)
