How to parse /proc/pid/cmdline

Question

I\'m trying to split the cmdline of a process on Linux but it seems I cannot rely on it to be separated by \'\\0\' characters. Do you know why sometimes the \'\\0\' character is

Answer 1

The /proc/PID/cmdline is always separated by NUL characters.

To understand spaces, execute this command:

cat -v /proc/self/cmdline "a b" "c d e"

EDIT: If you really see spaces where there shouldn't be any, perhaps your executable (intentionally or inadvertently) writes to argv[], or is using setproctitle()?

When the process is started by the kernel, cmdline is NUL-separated, and the kernel code simply copies the range of memory where argv[] was at process startup into the output buffer when you read /proc/PID/cmdline.