The goal is to run a command, ala system() or readpipe(), and capture the STDOUT and/or STDERR.

I find myself having to do this a lot, but especially when running basic Git commands.

• IPC::Open3 and IPC::Open2 — 5089 reverse dependencies
  • pro — in Perl core since v5.000 (change history)
• Capture::Tiny — 656 reverse dependencies
  • pro — can capture STDOUT, STDERR, or both
  • pro — can tee things, to send the output both to $captured_string as well as to the terminal
  • con — doesn't use wantarray to decide whether to return the output as a single string or split up into individual lines
• IPC::System::Simple — 130 reverse dependencies
  • pro — uses wantarray to determine whether to return the output as a single string or split up into individual lines
  • con — doesn't have the tee() functionality that Capture::Tiny does
  • con — can only capture STDOUT, never STDERR
• IPC::Run3 — 113 reverse dependencies
  • pro — portable (by using File::Temp for STDIN/STDOUT/STDERR, it works the same on Win32 as the others)
  • pro — actually, the more I think about it, the more I like this solution
• IPC::Cmd — 132 reverse dependencies
  • pro — in Perl core since v5.9.5
• IO::CaptureOutput — 44 reverse dependencies — marked "deprecated" in favor of Capture::Tiny
• System::Command — 5 reverse dependencies
  • background — This was created at the same time Git::Repository::Command was being created, and they have a nearly identical interface.
  • note — you should use the spawn() routine, if the other modules here appeal to you, unless you need the more-verbose interface of the rest of the module
  • con — doesn't have the tee() functionality that Capture::Tiny does
  • con — doesn't use wantarray to decide whether to return the output as a single string or split up into individual lines
    • (though it does have the loop_on() functionality)
  • pro — has the ability to specify a string that will be piped in via the processes' STDIN
  • con — doesn't have the ability to just capture STDOUT and leave STDERR untouched, to go to the user's terminal
• my own readpipe_args(), readpipe_args_chomp(), and readpipe_ultimate()
  • pro — they use wantarray to determine whether to return the output as a single string or split up into individual lines
  • con — they can only capture STDOUT, never STDERR
  • con — it's a bad idea to use Perl Golf in production scripts
• Forks::Super — More low-level than these others, which IMHO makes it much more flexible. Unfortunately, it errors out during installation due to many failed tests.

these incorporate and are based on Capture::Tiny

• Command::Runner — 3 reverse dependencies
  • con — it can either capture both STDOUT and STDERR, or capture them merged together (see _wrap() inside its source)
  • con — doesn't use wantarray to decide whether to return the output as a single string or split up into individual lines
    • (though runns the callback for each line returned, which means it always processes the outpu split up into individual lines)
• Capture::SystemIO — 0 reverse dependencies
  • con — always captures both STDOUT and STDERR, it doesn't have the ability to just capture one or the other
  • con — doesn't use wantarray to decide whether to return the output as a single string or split up into individual lines

random other ones

• Backticks
• about a trillion more