OSF

NAME

delta − Saves editing changes in a Source Code Control System (SCCS) file

SYNOPSIS

delta [-glist] [-m[MRlist]] [-nps] [-rSID] [-y[comment]] file ...  | -

The delta command is used to introduce into the named SCCS file any changes that were made to the file version retrieved by an SCCS get -e command.

FLAGS

-glistSpecifies a list of SIDs (deltas) that are to be ignored when the get command creates the g-file.  After you use this flag, get ignores the deltas in this list when it builds the g-file. 

-m[MRlist]
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 flag, delta reads MRs from the standard input.  If standard input is a tty, delta prompts you for the MRs. delta continues to take input until it reads End-of-File.  It always reads MRs before the comments (see the -y flag).  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. 

-nRetains the g-file, which is normally removed at completion of delta processing. 

-pWrites to standard output (in the format of the sccsdiff command) the SCCS file differences before and after the delta is applied.  (See the sccsdiff command for more information.) 

-rSIDSpecifies which delta is to be made to the SCCS file.  You must use this flag 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. 

-sSuppresses the information normally written to standard output on normal completion of the delta command. 

-y[comment]
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. 

DESCRIPTION

The delta command reads the g-files that correspond to the specified files (see the get command) and creates a new delta. 

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 flag.  You must also supply the -m flag if the v header flag is set.  (For more information on header flags, see the admin(1) command.)  delta reads standard input until it reaches End-of-File. 

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. 

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. 

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. 

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 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 re-edit the file and replace the identification keywords. 

To prevent the loss of keywords, use the admin command with the -f flag to specify the i option. 

EXAMPLES

     1.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, records the changes made by editing prog.c.  delta 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."

NOTES

Lines beginning with an SOH ASCII character (binary 001) cannot be placed in the SCCS file unless the SOH is quoted using a \ (backslash).  SOH has special meaning to SCCS and causes an error.  See the sccsfile(4) reference page. 

EXIT VALUES

For information about exit values, see the -m flag description. 

RELATED INFORMATION

Commands:  admin(1), bdiff(1), cdc(1), comb(1), get(1), prs(1), rmdel(1), sact(1), sccsdiff(1), sccshelp(1), unget(1), val(1), what(1). 

Files:  sccsfile(4). 

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