Perl code for parsing a text file and output a text file

[jhamb]

Hi,
This code is in Perl (just a trial, not tested) to parse a text file and output to another file.
It is used to delete lines that are not required and output lines that the user wants, to a new file.

The problems are:
1 This script is giving blank lines in the new file.
2 I have to remove a whole delimitter (#if FOR_LAB) from the text file.
3.The tool should be able to parse the file, and remove FOR_LAB’ed code, with out affecting the surrounding code, i.e.
I have to remove whole of the sequence of lines:

#if FOR_LAB
   DWORD dwSize = file.getFileSize();
   DWORD dwMinFileSize = sizeof(CVTableCfgFileHeader) +
            sizeof(CVTableCfgFileFracHdr) + sizeof(CVTableCfgFileSigDesc);
      if (dwSize < dwMinFileSize)
      {
         Error.Log(__FILE__, "CVT config file %s is too short.", pszFileName);
         return false;     // need at least one signal description to be useful
      }
#endif

not just the first 1..



Code:

#!/usr/local/bin/perl

#program to read cvtablebuild.cpp
#and write to cvtablebuild_final.cpp
#

$file = '/users/aj/files/cvtablebuild.cpp';
open(INFO, $file);                                   #opens file cvtablebuild.cpp
open(DATA, ">cvtablebuild_final.cpp");     #file to write data to
@lines = <INFO>;                                  #assigns lines to array

foreach $line (@lines) #go through each line in file
{
	if ($line ^#if FOR_LAB)
	{
		$line = ~ s/$line//;
	}

	DATA == $line;
	print DATA "\n";
}

close(INFO);                                             #closes file
close(DATA);

Thankq in advance, for any kind of help... :):)


Regards,
Anubhav Jhamb

[rohitbasu77]

[CODE=perl]#!/usr/bin/perl

$file = 'read';
$wrt = 'write';
open(info, $file);
open(data, ">>$wrt");

@lines = <info>;

foreach $lin (@lines){
#.............. ............... ......correct the search condition
if($lin =~ /^#FOR_LAB/){
#.............. ............... .....make the line blank
$lin = "";
}

print data "$lin";
}[/CODE]


regards
rohit

[nithinpes]

Hi,
This code is in Perl (just a trial, not tested) to parse a text file and output to another file.
It is used to delete lines that are not required and output lines that the user wants, to a new file.
The problems are:
1 This script is giving blank lines in the new file.
2 I have to remove a whole delimitter (#if FOR_LAB) from the text file.
3.The tool should be able to parse the file, and remove FOR_LAB’ed code, with out affecting the surrounding code, i.e.
I have to remove whole of the sequence of lines:

#if FOR_LAB
DWORD dwSize = file.getFileSiz e();
DWORD dwMinFileSize = sizeof(CVTableC fgFileHeader) +
sizeof(CVTableC fgFileFracHdr) + sizeof(CVTableC fgFileSigDesc);
if (dwSize < dwMinFileSize)
{
Error.Log(__FIL E__, "CVT config file %s is too short.", pszFileName);
return false; // need at least one signal description to be useful
}
#endif
not just the first 1..



Code:

#!/usr/local/bin/perl

#program to read cvtablebuild.cp p
#and write to cvtablebuild_fi nal.cpp
#

$file = '/users/aj/files/cvtablebuild.cp p';
open(INFO, $file); #opens file cvtablebuild.cp p
open(DATA, ">cvtablebuild_ final.cpp"); #file to write data to
@lines = <INFO>; #assigns lines to array

foreach $line (@lines) #go through each line in file
{
if ($line ^#if FOR_LAB)
{
$line = ~ s/$line//;
}

DATA == $line;
print DATA "\n";
}

close(INFO); #closes file
close(DATA);

Thankq in advance, for any kind of help... :):)


Regards,
Anubhav Jhamb

If you want to skip blank lines, you need not print them. And also, you need not put a "\n" while printing since you are not chopping newlines after reading input(using chomp). This will add unnecessary blank lines.
See the modified foreach loop:
[CODE=text]
foreach $line (@lines) #go through each line in file
{
next if ($line=~/^#if FOR_LAB/);
print DATA $line;
}
[/CODE]

This will remove lines begining with #if FOR_LAB. If your requirement is to remove all lines from '#if FOR_LAB' to '#endif', use the following method:

[CODE=text]
foreach $line (@lines) #go through each line in file
{
if ($line=~/^#if FOR_LAB/) {
$i=1; next;
}
if($i==1)
{
next unless($line=~/#endif/); ## skip upto #endif
$i=0; ##re-initialize
next; ## to skip #endif
}

print DATA $line;
}
[/CODE]

[KevinADC]

[CODE=perl]#!/usr/bin/perl

$file = 'read';
$wrt = 'write';
open(info, $file);
open(data, ">>$wrt");

@lines = <info>;

foreach $lin (@lines){
#.............. ............... ......correct the search condition
if($lin =~ /^#FOR_LAB/){
#.............. ............... .....make the line blank
$lin = "";
}

print data "$lin";
}[/CODE]


regards
rohit

You should read the question more carefully.

[jhamb]

Nithinpes,
Thanx for that loop code, I was just looking for that kind of job to be done. :)

Rohit,
Well, thank you too for correcting the search condition. Now I gotto know about it. :)

[jhamb]

One more thing I had to look upon:
The code should be able to do it for multiple files and directories, recursively.

But I would like to see working for single file first, before going further.
I will try writing some code by self. If get stuck, I'll post...

Anubhav Jhamb

[rohitbasu77]

You should read the question more carefully.

What wrong you find there.

[KevinADC]

What wrong you find there.

I have to remove whole of the sequence of lines:

not just the first 1..

[rohitbasu77]

I have to remove whole of the sequence of lines:

not just the first 1..

Your question is not clear to me.
write the original text and the modified text.

[KevinADC]

Your question is not clear to me.
write the original text and the modified text.

I did not write a question. It really does not matter anyway, nithinpes already posted a working solution to the original question.

[jhamb]

Sorry, for repetition of same post..
Please ignore this post... :):)

[jhamb]

Your question is not clear to me.
write the original text and the modified text.

Rohit,
KevinADC was just telling you to add lines in the loop to make up the task of removing all the sequence of lines in FOR_LAB'ed code. :):)

For instance the Input File content is as below:

if (file.open(pszFileName))
   {
                        pby = (char*)file.getBufferPointer();
#if FOR_LAB
   DWORD dwSize = file.getFileSize();
   DWORD dwMinFileSize = sizeof(CVTableCfgFileHeader) +
            sizeof(CVTableCfgFileFracHdr) + sizeof(CVTableCfgFileSigDesc);
      if (dwSize < dwMinFileSize)
      {
         Error.Log(__FILE__, "CVT config file %s is too short.", pszFileName);
         return false;     // need at least one signal description to be useful
      }
#endif

      pFileHdr = (CVTableCfgFileHeader*)pby;
      pby += sizeof(CVTableCfgFileHeader);
#if FOR_LAB
      if (strcmp(pFileHdr->szSignature, "CVT-CFG") != 0)
      {
         Error.Log(__FILE__, "CVT cfg file %s has wrong signature.", pszFileName);
         return false;
      }
      if (pFileHdr->version != iCVTCFGVERSION)
      {
         Error.Log(__FILE__, "Wrong version of CVT cfg. Found %d expecting %d in %s",
            pFileHdr->version, iCVTCFGVERSION, pszFileName);
         return false;
      }
      if (pFileHdr->iNumFrac > CVTableIndex::iMAX_FRACTIONS)
      {
         Error.Log(__FILE__, "CVT cfg file %s has too many fractions", pszFileName);
         return false;
      }
#endif
         // --- ok... ready to build the whole table ---

   CVTableIndex *pIdx = m_hTblIdx.Init(CVTableIndex::pszTBLIDXNAME, 
                                       SharedMemObjHandle<CVTableIndex>::omCREATE_RO);
#if FOR_LAB
      if (pIdx == NULL)
      {
         Error.Log(__FILE__, "Unable to create CVT table index.");
         return false;
      }
#endif

   int iTotalSignalCt = 0;
      for (int iFrac=0; iFrac < pFileHdr->iNumFrac; ++iFrac)
      {
         pFracHdr = (CVTableCfgFileFracHdr*)pby;
         pby += sizeof(CVTableCfgFileFracHdr);

#if FOR_LAB
         if (*pFracHdr->szFracName == 0 ||
              pFracHdr->iNumSigs > 5000    )
         {
            Error.Log(__FILE__, "CVT cfg file '%s' fraction header %d malformed.", 
                      pszFileName, iFrac);
            break;
         }
#endif

After parsing, the output file should be devoid of FOR_LAB code:

if (file.open(pszFileName))
   {
                        pby = (char*)file.getBufferPointer();

      pFileHdr = (CVTableCfgFileHeader*)pby;
      pby += sizeof(CVTableCfgFileHeader);
         // --- ok... ready to build the whole table ---

   CVTableIndex *pIdx = m_hTblIdx.Init(CVTableIndex::pszTBLIDXNAME, 
                                       SharedMemObjHandle<CVTableIndex>::omCREATE_RO);

   int iTotalSignalCt = 0;
      for (int iFrac=0; iFrac < pFileHdr->iNumFrac; ++iFrac)
      {
         pFracHdr = (CVTableCfgFileFracHdr*)pby;
         pby += sizeof(CVTableCfgFileFracHdr);

-- Jhamb

[rohitbasu77]

ok. thanks. As its a hassed statement. i thought you need to remove the hassed statement only.........

#if FOR_LAB.... this one in the whole code reperting any no of time.

ok. Any way thanks to every one.....

[jhamb]

Hey all,
I am done with the complete task..! :)

Code file name: perl_code.pl

$Start_Str = shift @ARGV;                  # to pass starting string
$End_Str = shift @ARGV;                    # to pass ending string
foreach $file (@ARGV)                       # to repeat the task for each file
{
   $Flag = 0;
   $filename = "Final_".$file;
   open(DATA, ">$filename");                    # file to write data to
   if (open(INFO, $file)) {
      @line = <INFO>;                             # assigns lines to array
      foreach $lines (@line) {                      # go through each line in file
         if (($lines=~ /$Start_Str/) || ($Flag == 1))
         {
            $Flag = 1;
            if ($lines=~ /$End_Str/ )
            {
               $Flag = 0;
            }
         }
         else
         {
            print DATA ($lines);
         }
      }
   }
}
print "Parsing is completed";
close(INFO);                                  # closes file
close(DATA);

This is command line and can be used for any input, for multiple numbers of files, without affecting the surrounding code.

I tried writing the following lines in command prompt:

C:\>PERL perl_code.pl "#if FOR_LAB" endif cvtablebuild.cp p 1.txt
Parsing is completed

Or can try for any input:

C:\>PERL perl_code.pl ANYTHING_ELSE endif cvtablebuild.cp p 1.txt
Parsing is completed

Output files are created as Final_cvtablebu ild.cpp and Final_1.txt

1.text:

   if (file.open(pszFileName))
   {
                        pby = (char*)file.getBufferPointer();
#if FOR_LAB
   DWORD dwSize = file.getFileSize();
   DWORD dwMinFileSize = sizeof(CVTableCfgFileHeader) +
            sizeof(CVTableCfgFileFracHdr) + sizeof(CVTableCfgFileSigDesc);
      if (dwSize < dwMinFileSize)
      {
         Error.Log(__FILE__, "CVT config file %s is too short.", pszFileName);
         return false;     // need at least one signal description to be useful
      }
#endif

      pFileHdr = (CVTableCfgFileHeader*)pby;
      pby += sizeof(CVTableCfgFileHeader);
#if FOR_LAB
      if (strcmp(pFileHdr->szSignature, "CVT-CFG") != 0)
      {
         Error.Log(__FILE__, "CVT cfg file %s has wrong signature.", pszFileName);
         return false;
      }
      if (pFileHdr->version != iCVTCFGVERSION)
      {
         Error.Log(__FILE__, "Wrong version of CVT cfg. Found %d expecting %d in %s",
            pFileHdr->version, iCVTCFGVERSION, pszFileName);
         return false;
      }
      if (pFileHdr->iNumFrac > CVTableIndex::iMAX_FRACTIONS)
      {
         Error.Log(__FILE__, "CVT cfg file %s has too many fractions", pszFileName);
         return false;
      }
#endif
         // --- ok... ready to build the whole table ---

   CVTableIndex *pIdx = m_hTblIdx.Init(CVTableIndex::pszTBLIDXNAME, 
                                       SharedMemObjHandle<CVTableIndex>::omCREATE_RO);
#if FOR_LAB
      if (pIdx == NULL)
      {
         Error.Log(__FILE__, "Unable to create CVT table index.");
         return false;
      }
#endif

   int iTotalSignalCt = 0;
      for (int iFrac=0; iFrac < pFileHdr->iNumFrac; ++iFrac)
      {
         pFracHdr = (CVTableCfgFileFracHdr*)pby;
         pby += sizeof(CVTableCfgFileFracHdr);

#if FOR_LAB
         if (*pFracHdr->szFracName == 0 ||
              pFracHdr->iNumSigs > 5000    )
         {
            Error.Log(__FILE__, "CVT cfg file '%s' fraction header %d malformed.", 
                      pszFileName, iFrac);
            break;
         }
#endif

Final_1.txt:

   if (file.open(pszFileName))
   {
                        pby = (char*)file.getBufferPointer();

      pFileHdr = (CVTableCfgFileHeader*)pby;
      pby += sizeof(CVTableCfgFileHeader);
         // --- ok... ready to build the whole table ---

   CVTableIndex *pIdx = m_hTblIdx.Init(CVTableIndex::pszTBLIDXNAME, 
                                       SharedMemObjHandle<CVTableIndex>::omCREATE_RO);

   int iTotalSignalCt = 0;
      for (int iFrac=0; iFrac < pFileHdr->iNumFrac; ++iFrac)
      {
         pFracHdr = (CVTableCfgFileFracHdr*)pby;
         pby += sizeof(CVTableCfgFileFracHdr);

Thanks to everyone who helped.. :):)
Please let me know if you find something more to add in the code.