#!/bin/bash# patt-matching.sh# Pattern matching  using the # ## % %% parameter substitution operators.var1=abcd12345abc6789pattern1=a*c  # * (wild card) matches everything between a - c.echoecho "var1 = $var1"           # abcd12345abc6789echo "var1 = ${var1}"         # abcd12345abc6789                              # (alternate form)echo "Number of characters in ${var1} = ${#var1}"echoecho "pattern1 = $pattern1"   # a*c  (everything between 'a' and 'c')echo "--------------"echo '${var1#$pattern1}  =' "${var1#$pattern1}"    #         d12345abc6789# Shortest possible match, strips out first 3 characters  abcd12345abc6789#                                     ^^^^^               |-|echo '${var1##$pattern1} =' "${var1##$pattern1}"   #                  6789      # Longest possible match, strips out first 12 characters  abcd12345abc6789#                                    ^^^^^                |----------|echo; echo; echopattern2=b*9            # everything between 'b' and '9'echo "var1 = $var1"     # Still  abcd12345abc6789echoecho "pattern2 = $pattern2"echo "--------------"echo '${var1%pattern2}  =' "${var1%$pattern2}"     #     abcd12345a# Shortest possible match, strips out last 6 characters  abcd12345abc6789#                                     ^^^^                         |----|echo '${var1%%pattern2} =' "${var1%%$pattern2}"    #     a# Longest possible match, strips out last 12 characters  abcd12345abc6789#                                    ^^^^                 |-------------|# Remember, # and ## work from the left end (beginning) of string,#           % and %% work from the right end.echoexit 0