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readproctitle(8) System Manager's Manual readproctitle(8)


readproctitle - maintains an automatically rotated log in memory for inspection by ps(1).

readproctitle is available in daemontools 0.75 and above.


readproctitle L D


L consists of any number of arguments. D is one argument consisting of at least five dots.

readproctitle reads data into the end of D, shifting D to the left to make room. This means that the most recent data is visible to process-listing tools such as ps(1). readproctitle always leaves three dots at the left of D.

For example, if

readproctitle io errors: ....................

reads the data

fatal error xyz
warning abc

then its command-line arguments change to

readproctitle io errors: ... xyz!warning abc!

with a newline character in place of each !. Process-listing tools typically show the newline character as ? or \n.

readproctitle exits when it reaches the end of input.

Beware that most implementations of ps(1) have small argument-length limits. These limits apply to the total length of readproctitle L D. I have not seen a system with a limit below 512 bytes.


supervise(8), svc(8), svok(8), svstat(8), svscanboot(8), svscan(8), fghack(8), pgrphack(8), multilog(8), tai64n(8), tai64nlocal(8), setuidgid(8), envuidgid(8), envdir(8), softlimit(8), setlock(8), ps(1)