unitproc/bktemp-checkTar

   1 #!/bin/bash
   2
   3 # Desc: Checks that a valid tar archive exists, creates one otherwise
   4
   5 # Yell, Die, Try Three-Fingered Claw technique
   6 # Ref/Attrib: https://stackoverflow.com/a/25515370
   7 yell() { echo "$0: $*" >&2; }
   8 die() { yell "$*"; exit 111; }
   9 try() { "$@" || die "cannot $*"; }
  10
  11 checkTar() {
  12     # Desc: Checks that a valid tar archive exists, creates one otherwise
  13     # Usage: checkTar [ path ]
  14     # Input: arg1: path of tar archive
  15     # Output: exit code 0: tar exists and is valid
  16     # Depends: try, tar, date
  17     local PATH_TAR="$1"
  18
  19     # Check if file is a valid tar archive
  20     if tar --list --file="$PATH_TAR" 1>/dev/null 2>&1; then
  21         ## T1: return success
  22         return 0;
  23     else
  24         ## F1: Check if file exists
  25         if [[ -f "$PATH_TAR" ]]; then
  26             ### T: Rename file
  27             try mv "$PATH_TAR" "$PATH_TAR""--broken--""$(date +%Y%m%dT%H%M%S)";
  28         else
  29             ### F: -
  30             :
  31         fi
  32         ## F2: Create tar archive
  33         try tar --create --file="$PATH_TAR" --files-from=/dev/null;
  34     fi
  35 } # checks if arg1 is tar; creates one otherwise