I frequency use pidof command with strace system call tracer.
strace can trace MULTIPLE processes specified with "-p $PID"
arguments like:
strace -p 1 -p 1030 -p 3043
Sometimes I want to do as following
strace -p $(pidof httpd)
However, above command line doesn't work because -p option
is needed for specifying a pid. pidof uses a whitespace as
a separator. For passing the output to strace, the separator
should be replaced with ' -p '.
This maybe not a special to my use case.
This commit introduces -S option that allows a user to specify a
separator the one wants.
$ ./pidof bash
./pidof bash
24624 18790 12786 11898 11546 10766 7654 5095
$ ./pidof -S ',' bash
./pidof -S ',' bash
24624,18790,12786,11898,11546,10766,7654,5095
$ ./pidof -S '-p ' bash
./pidof -S '-p ' bash
24624-p 18790-p 12786-p 11898-p 11546-p 10766-p 7654-p 5095
$ ./pidof -S ' -p ' bash
./pidof -S ' -p ' bash
24624 -p 18790 -p 12786 -p 11898 -p 11546 -p 10766 -p 7654 -p 5095
$ strace -p $(./pidof -S ' -p ' bash)
strace -p $(./pidof -S ' -p ' bash)
strace: Process 24624 attached
strace: Process 18790 attached
strace: Process 12786 attached
...
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
A difference in behaviour between the sysvinit and procps pidof
was that the procps one would sometimes not find process that
the sysvinit one did.
The difference is that if a space is found in argv[0] then sysvinit
would look at cmd for a match. This isn't perfect and more of a
best guess but does often work.
procps pidof now follows the same "standard". The most obvious
difference is with kde based processes and incoming ssh connections
with sshd.
References:
GitLab issue #4https://gitlab.com/procps-ng/procps/issues/4https://github.com/limingth/sysvinit/blob/master/sysvinit-2.88dsf/src/killall5.c#L800
The function pid_link tries to handle programs which contain very
long paths to their executables. If 1024 bytes are not enough to
contain the path, the loop wants to get more and more space until
the path can fit.
The loop's condition does not fit though.
readlink will never return a value higher than its supplied size
limit, which is "path_alloc_size - 1", therefore the loop-check of
"len == path_alloc_size" will always be false: the loop will never
be repeated.
While at it, the if-condition inside the loop's body can be omitted,
because it is always true.
Benno Schulenberg suggested some changes to the help messages
to provide some consistency and clarity for both the users and
translators of procps.
The test needed to be updated as the pmap output changed too.
Signed-off-by: Craig Small <csmall@enc.com.au>
To assist translators, the help lines are split so that each translation
chunk has one option. This gives bonus of if we add or change an option,
only that option remains untranslated rather than the entire help block.
Reference:
http://www.freelists.org/post/procps/procpsng-for-Translation-Project,1
Signed-off-by: Craig Small <csmall@enc.com.au>
This commit introduces support for special %PPID value that
can be passed to the -o option as a substitution for parent
PID. It also allows users to use two additional separators
for omitted PIDs - colon and semicolon.
As the sysvinit becomes obsolete, some of the bundled tools
need to find a new home. The procps-ng project seems to be
the most suitable project for adopting the pidof tool.
This commit introduces a redesigned version of pidof
that satisfies the LSB requirements.
In corner cases the behaviour might differ from the former
one as the new version doesn't use any stat(2) calls.
