• The command test allows two strings or two integers to be compared.
  • A shorthand version uses [ and ] around the arguments.
    WARNING: be very careful to put the spaces in correctly!
  • The syntax is very different for comparing numbers or strings (see help test for the syntax options).
  • test can also be used to check the status of files (whether they exist, are writable, etc.)
  test $a = my         string equality
  [ $a = my ] as above
  [ $a -eq 2 ] tests numerical equality
  [ 11 -gt 2 ] compares numbers (greater than)
  [ 11 > 2 ] does NOT do numerical comparison
  [ -e im1.nii.gnii.gz ] tests if file exists
  Note: for non-integer numerical comparisons, see bc