DELTA(1)

NAME
delta - make an SCCS delta

SYNOPSIS
delta [-s] [-n] [-rsid] [-glist] [-yhistory] [-mmrs] [-p] name ...

DESCRIPTION
Delta adds a delta to each named SCCS file. If a directory is named, delta behaves 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 are silently ignored. If a name of ``-'' is given, the standard input is read; each line of the standard input is taken to be the name of an SCCS file to be processed. Again, non-SCCS files, and unreadable files are silently ignored. (If a name of ``-'' is given the y keyletter must be present; see below.)

A get of many SCCS files, followed by a delta of those files should be avoided when the get generates a large amount of data. Instead, multiple get-delta sequences should be used.

Comments about the purpose of the delta(s) are supplied (once, and only once) either from the standard input, or by using the y argument. If one supplies the comments through the standard input, and the standard input is a terminal (as determined by a successful gtty (2) call), the program will prompt (on the standard output) with ``comments? ''. Otherwise, no prompt is printed. A newline preceded by a ``\'' may be used to make the entering of the comments more convenient. The first newline not preceded by a ``\'' terminates the comments response. The y argument is used to supply comments on the command line; if it is given the ``comments?'' question is not printed, and the standard input is not read.

If there is a v flag in the file (see admin (1)) the prompting is somewhat different. As the comments are solicited only once, if the first file processed has a v flag then all files processed must have a v flag (any files that don't will cause a diagnostic message and won't be processed; processing will continue with the next file). The inverse is also true.

When a file has a v flag, before prompting for ``comments? '' delta will prompt for ```MRs? '' (again, the prompt is only printed if the standard input is a terminal). MR numbers are read from the standard input separated by blanks and/or tabs. The same continuation rules apply as above. When an unadorned newline is read, delta will prompt for ``comments? '' as described above. If the v flag has a value, it is taken to be the name of a program (or shell procedure) which will validate the correctness of the MR numbers. This program is executed with the first argument having the value of the %M% identification keyword, a second argument of the value of the %Y% identification keyword, and third and subsequent arguments being the MR numbers. If a non-zero exit status is returned from this program delta will terminate (it is assumed that the MR numbers were not all valid). The m argument is used to supply MR numbers on the command line; if it is given the ``MRs? '' question is not printed, and the standard input is not read.

The following description is written as though only one SCCS file were named; the process of making a delta is equivalent for each file. (Note that the effects of any keyletter arguments apply independently to each SCCS file, and that the same comments are used for all files.)

The g argument specifies a list (see get (1) for the definition of <list>) of deltas which are to be marked ignored when the file is accessed at the change level created by this delta. (See the description of the l-file format in get (1)). A delta should only be ignored when the problem that caused the creation of the delta being ignored is no longer a problem at the change level created by this delta.

The p argument causes delta to print the differences that constitute the delta on the standard output.

Delta makes a delta by ``getting'' the named file (see get (1)) at the SID specified by the r keyletter (this SID must be listed in the p-file ), or at the same SID that was used when the get command was executed with the e argument by the user executing delta (if the user executing delta is listed more than once in the p-file, the r argument must be supplied). The ``gotten'' file is then compared with the g-file ; the differences between the two files constitute the delta.

When the comparison is finished, delta prints the SID of the new delta, followed by the number of lines inserted, deleted, and unchanged. The s argument suppresses this printing. Normally, the g-file is removed after the delta is made. The n argument suppresses the removal.

Delta will ignore hangups if it is already ignoring interrupts.

FILES

g-file
    See get for an explanation of the g-file.

p-file
    Information from get.
    q-file    Replacement for the
    p-file. The naming convention is the same as that for the p-file (see get ).

x-file
    Replacement for the SCCS file. The naming convention is the same as that for the p-file (see get ).

z-file
    Lockout file; see get (1).

d-file
    ``Gotten'' file; temporary. The naming convention is the same as that for the p-file (see get ).

/usr/bin/bdiff
    Program to compute differences between the ``gotten'' file and the g-file.

SEE ALSO
get(1), admin(1), prt(1), help(1), sccsfile(5), bdiff(1)
SCCS/PWB User's Manual by L. E. Bonanni and A. L. Glasser.

DIAGNOSTICS
Use help (1) for explanations.