Super “strace” perl script to assist with debugging programs that spawn child processes.

Last Updated on October 15, 2007 EDT by

If you have ever ran into a problem with trying to strace apache or other processes that spawn children, then this script will help you out greatly. This small perl script will grab all of the PID’s of the current process and its children and then run an strace command on all of them to provide strace output from all of apache. You can modify the strace line to your liking as well as the log names, by default it logs to a file based on date and time to the /tmp directory. Code included, click ‘Read More’.

#!/usr/bin/perl


# Do we have any input?

if(!$ARGV[0]) {

  print "Super strace, will strace a running application and all of its children.\nUsage: $0 \nExample: $0 apache2\n";

  exit;

}

# get the data we need!

@pids = `pgrep @ARGV[0]`;

# this is the old method, if pidof doesn't exist uncomment if the above breaks

#@pids = `ps auxwwf | grep apache | awk \'\{ print \$2\}\'`;

# get some variables for the current time! Gotta be iso 8601 YYYY-MM-DDThh:mm:ssTZD (eg 1997-07-16T19:20:30+01:00)

#my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime time;

$date = `date +%FT%H:%M:%S%:z`;

chomp ($date);

#$year += 1900;

#$mon += 1;

#$date = "$year-$mon-$mdayT$hour:$min:$sec";

# the strace command! this can be replaced with any command

$go="strace -f -s 40000 -o /tmp/sstrace-$date";

# the separator

$sep = " -p ";

$i=0;

foreach $pid (@pids) {

chomp ($pid);

$go = $go . $sep .  $pid;

$i++;

}

print $go . "\n";

exec $go;

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