Be aware that the global options must be specified on the command line before the Perforce command. Options specified after the Perforce command will not be interpreted as global options, but as options for the command being invoked. It is therefore possible to have the same command line option appearing twice in the same command, being interpreted differently each time.

For example, the command p4 -c anotherclient edit -c 140 file.c will open file file.c for edit in pending changelist 140 under client workspace anotherclient.

The -x option is useful for automating tedious tasks; a user adding several files at once could create a text file with the names of these files and invoke p4 -x textfile add to add them all at once.

The -x option can be extremely powerful, as powerful as whatever generates its input. For example, a UNIX developer wishing to edit any file referring to an included file.h file, for instance, could grep -l file.h *.c | cut -f1 -d: | p4 -x - edit.

In this example, the grep command lists occurrences of file.h in the *.c files, the -l option tells grep to list each file only once, and the cut command splits off the filename from grep's output before passing it to the p4 -x - edit command.

The -s option can be useful in automated scripts.

For example, a script could be written as part of an in-house build process which executes p4 -s commands, discards any output lines beginning with "info:", and alerts the user if any output lines begin with "error:".

Python developers will find the -G option extremely useful for scripting. For instance, to get a dictionary of all fields of a job whose ID is known, use the following:

job_dict = marshal.load(os.popen('p4 -G job -o ' + job_id, 'rb'))

In some cases, it may not be intuitively obvious what keys are used by the application. If you pipe the output of any p4 -G invocation to the following script, you will see every record printed out in key/value pairs:

#!/usr/local/bin/python

import marshal, sys

try:
    num=0
    while 1:
        num=num+1
        print '\n--%d--' % num
        dict = marshal.load(sys.stdin, 'rb')
        for key in dict.keys(): print "%s: %s" % (key,dict[key])

except EOFError: pass

Python developers on Windows should be aware of potential CR/LF translation issues; in the example, it is necessary to call marshal.load() to read the data in binary ("rb") mode.

At present, the progress indicator requested when you use the -I option is only available with p4 -I submit and p4 -I sync -q.

Some uses of the global options are absurd.

For example, p4 -c workspace help provides exactly the same output as p4 help.