I'm preparing a 30 minute presentation comparing C to Perl for my club. The audience fellow undergraduates with some exposure to C and no exposure to Perl. This is not official homework for a grade. I plan to include a pointer to this thread in my presentation.

Below are two functions, one in Perl, one in C. Both are supposed to replace Microsoft \n\r with hmtl <p></p> tags. Both functions were kludged up by banging randomly on the problem until I more or less got the right answer. For what it is worth, I wrote the C function two years ago because I was too lazy to tackle perl.

I would probably benefit from suggestions like "just open the file in text mode.". However, for my immediatepurpose I'm most interested in knowing:

Do these functions do approximately the same thing?
Is there an cleaner way to do this in C?

C

extern char * danCGIReplacedCRLF(char * szFixMe){
    int i,j,iLen=0,iNewLen=0;
    int iCRLFcount=0;
    char* szResult=NULL;

    iLen=strlen(szFixMe);

    for (i=0;i<=iLen;i++){
        if (szFixMe[i]==(int) '\n' || szFixMe[i]==(int) '\r')
            iCRLFcount++;
    }

// need space for first <p> +NULL+ text 
// + replace each CR &LF + last " <\p>"
    iNewLen=3+1+strlen(szFixMe)+(iCRLFcount*8)+5;
        szResult = malloc(iNewLen);

        if (szResult){
        szResult[0]='<';
        szResult[1]='p';
        szResult[2]='>';
        szResult[3]='\0';
        i=0;
        j=3;

        while (i<=iLen)
            if (szFixMe[i]==(int) '\n' || szFixMe[i]==(int) '\r'){
                strcat(szResult," </p><p>");
                j+=8;
                // deal with Newline CR pairs
                if(szFixMe[i]==(int) '\n' && szFixMe[i+1]==(int) '\r'
                    || szFixMe[i]==(int) '\r' || szFixMe[i+1]==(int) '
+\n')
                    i+=2;
                else
                    i++;
            }else{
                szResult[j]=szFixMe[i];
                j++;
                szResult[j]='\0'; //dest string in strcat needs termin
+ating \0
                i++; 
            } //outer loop & if statement

//end of new document needs </p> to match at start
                strcat(szResult," </p>");
    } // if(szResult !=NULL )

    return szResult;
}
[download]

perl

sub MakePtag{
  my ($fixme)=@_;              # take in our parameters
  $fixme='<p>'.$fixme;         # Prepend a <p> tag to our string
  $fixme=~s|(\r\n)|<\\p><p>|g; # replace all \r\n with <\p><p>
  $fixme.='<\p>';              # Append closing <\p> tag
  return $fixme;                
}
[download]

email: mandog

In reply to C vs perl by mandog

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