Shell Programming and Scripting

$ 
$ 
$ # list the xml files in current directory
$ ls -1 *.xml
file1.xml
file2.xml
file3.xml
$ 
$ # display the content of each xml file
$ cat -n file1.xml
     1    <?xml version="1.0"?>
     2    <catalog>
     3       <book id="bk101">
     4          <title>XML Developer's Guide</title>
     5          <genre>Computer</genre>
     6          <price>44.95</price>
     7       </book>
     8       <book id="bk102">
     9          <title>Midnight Rain</title>
    10          <genre>Fantasy</genre>
    11          <price>5.95</price>
    12       </book>
    13    </catalog>
$ 
$ cat -n file2.xml
     1    <?xml version="1.0"?>
     2    <catalog>
     3       <book id="bk103">
     4          <title>Maeve Ascendant</title>
     5          <genre>Fantasy</genre>
     6          <price>24.99</price>
     7       </book>
     8       <book id="bk104">
     9          <title>Oberon's Legacy</title>
    10          <genre>Fantasy</genre>
    11          <price>29.99</price>
    12       </book>
    13    </catalog>
$ 
$ cat -n file3.xml
     1    <?xml version="1.0"?>
     2    <catalog>
     3       <book id="bk105">
     4          <title>The Sundered Grail</title>
     5          <genre>Fantasy</genre>
     6          <price>5.95</price>
     7       </book>
     8       <book id="bk106">
     9          <title>Lover Birds</title>
    10          <genre>Romance</genre>
    11          <price>4.95</price>
    12       </book>
    13    </catalog>
$ 
$ # display the content of the Perl program
$ # the inline comments should be self-explanatory
$ cat -n searchandprint.pl
     1    #!/usr/bin/perl -w
     2    # Usage: perl searchandprint.pl <value> <directory>
     3    $search = $ARGV[0];
     4    # if directory is specified then search that,
     5    # otherwise look in the current directory
     6    if (defined $ARGV[1]) {$pattern = $ARGV[1]."/*.xml"}
     7    else {$pattern = "*.xml"}
     8    $found = 0;
     9    while (defined ($file = glob $pattern)) {
    10      print "Checking $file ... \t";
    11      open (F, $file) or die "Can't open $file: $!";
    12      while (<F>) {
    13        if ($found) {print}
    14        elsif (/$search/) {
    15          print "found the value; now printing the file...\n","="x80,"\n";
    16          # print the array; flush;
    17          # print current line; set $found to 1
    18          foreach (@lines) {print}
    19          @lines = ();
    20          print;
    21          $found = 1;
    22        } else {
    23          push @lines, $_;
    24        }
    25      }
    26      close (F) or die "Can't close $file: $!";
    27      @lines = ();
    28      if ($found == 0) {print "nothing here; moving on...\n"}
    29      else {$found = 0}
    30      print "="x80,"\n";
    31    }
$ 
$ # now run the Perl program
$ perl searchandprint.pl 5.95
Checking file1.xml ...     found the value; now printing the file...
================================================================================
<?xml version="1.0"?>
<catalog>
   <book id="bk101">
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
   </book>
   <book id="bk102">
      <title>Midnight Rain</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
   </book>
</catalog>
================================================================================
Checking file2.xml ...     nothing here; moving on...
================================================================================
Checking file3.xml ...     found the value; now printing the file...
================================================================================
<?xml version="1.0"?>
<catalog>
   <book id="bk105">
      <title>The Sundered Grail</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
   </book>
   <book id="bk106">
      <title>Lover Birds</title>
      <genre>Romance</genre>
      <price>4.95</price>
   </book>
</catalog>
================================================================================
$ 
$

$ 
$ 
$ for i in *.xml; do
>   echo "Checking file => $i..."
>   grep 5.95 $i 1>/dev/null 2>&1
>   if [ $? -eq 0 ]; then
>     cat $i
>   fi
> done
Checking file => file1.xml...
<?xml version="1.0"?>
<catalog>
   <book id="bk101">
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
   </book>
   <book id="bk102">
      <title>Midnight Rain</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
   </book>
</catalog>
Checking file => file2.xml...
Checking file => file3.xml...
<?xml version="1.0"?>
<catalog>
   <book id="bk105">
      <title>The Sundered Grail</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
   </book>
   <book id="bk106">
      <title>Lover Birds</title>
      <genre>Romance</genre>
      <price>4.95</price>
   </book>
</catalog>
$ 
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