A correction to my previous comment:
<https://bugs.launchpad.net/ubuntu/+source/procps/+bug/295876/comments/3> states that pgrep gets the process' name from /proc/<pid>/stat, not /proc/<pid>/status, as I wrote, and appears to be correct.
cat /proc/22351/stat 22351 (chromium-browse) S 1616 1829 1829 0 -1 4194560 31046 20451 701 0 468 160 6 2 20 0 31 0 355501 1271119872 38692 18446744073709551615 94135085649920 94135125690420 140723151897424 140723151896160 140132228684269 0 0 4096 81923 0 0 0 17 3 0 0 64 0 0 94135127791120 94135129570812 94135143915520 140723151902368 140723151902426 140723151902426 140723151904717 0
/proc/<pid>/status itself gets its info from /proc/<pid>/stat and /proc/<pid>/statm.
A correction to my previous comment:
<https:/ /bugs.launchpad .net/ubuntu/ +source/ procps/ +bug/295876/ comments/ 3> states that pgrep gets the process' name from /proc/<pid>/stat, not /proc/<pid>/status, as I wrote, and appears to be correct.
cat /proc/22351/stat 51615 94135085649920 94135125690420 140723151897424 140723151896160 140132228684269 0 0 4096 81923 0 0 0 17 3 0 0 64 0 0 94135127791120 94135129570812 94135143915520 140723151902368 140723151902426 140723151902426 140723151904717 0
22351 (chromium-browse) S 1616 1829 1829 0 -1 4194560 31046 20451 701 0 468 160 6 2 20 0 31 0 355501 1271119872 38692 184467440737095
/proc/<pid>/status itself gets its info from /proc/<pid>/stat and /proc/<pid>/statm.