bash字符串匹配

#!/bin/sh
 
 
 foo()
 {
     local basedir=$1
     local all_entries=`ls -c`
 
 
     for entry in $all_entries
     do  
         if test -d $entry; then
             cd $entry&&foo ${basedir}/$entry;cd - >/dev/null
         else
             if [[ $entry =~ .+\.(cpp|cc|h|hpp) ]]; then # 看这里
                 #echo $basedir/$entry
                 source_files="$source_files $basedir/$entry"
             fi  
         fi  
     done
 }
 
 
 foo .
 echo $source_files
 
 
 An additional binary operator, =~, is available, with the same precedence as == and !=.  When it is used, the string to the right of the operator is considered an extended regular expression and matched accordingly (as in  regex(3)).   The  return value  is  0 if the string matches the pattern, and 1 otherwise.  If the regular expression is syntactically incorrect, the conditional expression's return value is 2.