The following is being reported against monitoring-plugins-v2.1.1-39-g8095, though it applies as well to earlier releases.
There is a problem with the manner in which check_procs looks for command-line arguments (the "-a" option): -a, --argument-array=STRING Only scan for processes with args that contain STRING. The problem is that internally, check_procs depends on some variant of "ps" to scan for processes. And these days, many operating systems by default limit the length of the command-line string returned by "ps" to perhaps 80 characters or so. In the configuration and compilation of check_procs, an attempt is being made to overcome this limit, via the configured definition of PS_COMMAND placed into the config.h file by configure. Here I show the value produced on my Linux machine: #define PS_COMMAND "/bin/ps axwo 'stat uid pid ppid vsz rss pcpu comm args'" The problem is, a single "w" option only widens the "ps" output a bit, and not necessarily enough to encompass the target string a user is looking for with the check_procs -a option. (Processes can have very long argument lists, and the distinguishing string you need to identify a particular process of interest might not appear until close to the end.) The Linux "man ps" output says this about the "w" option: w Wide output. Use this option twice for unlimited width. So my request here is that the derivation of the PS_COMMAND value, at least on Linux platforms, be modified to use the "axwwo" options instead of the "axwo" options. Alas, my configure-fu is quite limited, and my git-fu is nonexistent, so I can't propose exact code changes.