File Replacement Help

Shell Programming and Scripting
1

Hi all,

I have two files, one is a base file and the other is a dependency file.

I need to replace a section in the base file (File A) with a section from the dependency file (File B), for example:

File A:
...

<TagName>
  <TagA>MyBaseFile</TagA>
  <TagB>MyBaseFileID</TagB>
</TagName>
<TagName>
  <TagA>Other</TagA>
  <TagB>OtherID</TagB>
</TagName>

...

I need to replace the 'TagName' section (in bold) with the section extracted from File B:

...

<TagName>
  <TagA>MyFile</TagA>
  <TagB>12345</TagB>
</TagName>

...

so File A should look like:

...

<TagName>
  <TagA>MyFile</TagA>
  <TagB>12345</TagB>
</TagName>
<TagName>
  <TagA>Other</TagA>
  <TagB>OtherID</TagB>
</TagName>

...

Any idea how this can be achieved in Shell/AWK or Perl (only basic Perl as I wont have the ability to upload new libraries to a server).

2

Invoke this with the dependecy file (file-B) as the first argument and the base file (file-A) as stdin or the second and subsequent arguments:

undef $/;

# slurp in dependency file

my $depfile = shift(@ARGV);

open FH, '<', $depfile or die $depfile;
my $tag = <FH>;
close FH;

print $tag;

# slurp in the base file

$_ = <>;

# replace section with the dependecy file

s{<TagName>\s*<TagA>MyBaseFile</TagA>\s*<TagB>MyBaseFileID</TagB>\s*</TagName>\s*}{$dep}ms;

print;
3

Hi Ludwig!

Thanks for the reply.

Will this still work where File A has multiple <TagName> sections? will it only replace one <TagName> section that I am concerned about?

File A has numerous <TagName> sections, I only want to replace one (could appear anywhere) where the <TagName><TagA> section has a value of say 'MyBaseFile' etc...

4

What I supplied will replace the first instance of <TagA>MyBaseFile</TagA> in the file. Depending on how complicated your files actually are (I assume that what you supplied was a sample), you may want to look at xml parsing modules which can give you very fine control over what is selected..

5

Hi Ludwig,

My base file looks like this:

<TagName>
<TagA>/MyBasePath/MyBaseFile/</TagA>
<TagB>MyBasePath/MyBaseFile/FileA</TagB>
</TagName>
<TagName>
<TagA>/MyBasePath/MyBaseFile/</TagA>
<TagB>MyBasePath/MyBaseFile/FileB</TagB>
</TagName>
<TagName>
<TagA>/MyBasePath/MyBaseFile/</TagA>
<TagB>MyBasePath/MyBaseFile/FileC</TagB>
</TagName>

My dependency file looks like this:

<TagName>
<TagA>/MyDepPath/MyDepFile/</TagA>
<TagB>MyDepPath/MyDepFile/FileA</TagB>
</TagName>
<TagName><TagA>/MyDepPath/MyDepFile/</TagA>
<TagB>MyDepPath/MyDepFile/FileB</TagB>
</TagName>
<TagName>
<TagA>/MyDepPath/MyDepFile/</TagA>
<TagB>MyDepPath/MyDepFile/FileC</TagB>
</TagName>

I need to replace the section in bold only in the base file by copying the dependency section into the base file section.

6

How do you select which section in the base file is to be replaced by which section in the dependency file?