Unix - Engineering

Q1:

Which option will be used with ps command to show the entire command line of the process being run?

A -4

B -f

C -1

D -2

E None of the above

ANS:B - -f

ps has many options. On operating systems that support the SUS and POSIX standards, ps commonly runs with the options -ef, where "-e" selects every process and "-f" chooses the "full" output format. Another common option on these systems is -l, which specifies the "long" output format.

Most systems derived from BSD fail to accept the SUS and POSIX standard options because of historical conflicts (for example, the "e" or "-e" option will cause the display of environment variables). On such systems, ps commonly runs with the non-standard options aux, where "a" lists all processes on a terminal, including those of other users, "x" lists all processes without controlling terminals and "u" adds a column for the controlling user for each process. Note that, for maximum compatibility when using this syntax, there is no "-" in front of the "aux". Also you can add 'ww' after aux, like "ps auxww" for complete information about the process including all parameters.