Extract value from process environment

Question

I need to extract information from a process environment (/proc/<PID>/environ). The content of those files is separated by null bytes, so I thought I'd use xargs to output the values line by line:

xargs -0 echo < /proc/2342/environ

However, this seems to output everything in one line, just separated by spaces instead of null characters.

Answer 1

If you want to use xargs you need to tell it to process the input one line at a time (-L1), otherwise echo will output the entire input at once (thus mangling all input lines into a space-separated string).

xargs -0 -L1 echo < /proc/2342/environ

You don't need the redirection, though, since xargs can read the input file directly (parameter -a), and echo is the default command, so you can omit that too:

xargs -0 -L1 -a /proc/2342/environ

Alternatively, you could achieve the same result by using tr to replace null characters with newlines:

tr '\0' '\n' < /proc/2342/environ