|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
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)