Module Name:	doc
Committed By:	agc
Date:		Tue Jan 15 13:23:22 UTC 2002

Modified Files:
	doc: pkg-CHANGES

Log Message:
Note addition of Erik E. Fair's shlock utility, with sources taken from
NetBSD-current, to the NetBSD Packages Collection.

The shlock command can create or verify a lock file on behalf of a
shell or other script program.  When it attempts to create a lock
file, if one already exists, shlock verifies that it is or is not
valid.  If valid, shlock will exit with a non-zero exit code.  If
invalid, shlock will re- move the lock file, and create a new one.

shlock uses the rename(2) system call to make the final target lock
file, which is an atomic operation (i.e.  "dot locking", so named for
this mech- anism's original use for locking system mailboxes).  It
puts the process ID ("PID") from the command line into the requested
lock file.

shlock verifies that an extant lock file is still valid by using
kill(2) with a zero signal to check for the existence of the process
that holds the lock.

This package is only for Solaris and Linux platforms at present.


To generate a diff of this commit:
cvs rdiff -r1.5777 -r1.5778 doc/pkg-CHANGES

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.