How to extract a range of text from a file

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Hi,

I am trying to extract a range of text from an input file "Test.txt"
The range starts from the occurrence of a string stored in pfst[0] till the string stored in pfet[0]. The final o/p is stored in the file "PerformSectionExtract.txt".

The string values prints fine before the parsing, but NULL values are printed after entering the parsing mechanism. Below is my code :

C

char pfst[1500][50];
char pfet[1500][50];

char fileOrig[MAX_PATH] = "Test.txt";
char fileRepl2[MAX_PATH] = "PerformSectionExtract.txt";

FILE *fp1, *fp2, *fp3, *fp4;
fp1 = fopen(fileOrig,"r+");
fp4 = fopen(fileRepl2,"w+");



while(fgets(buffer,MAX_LEN_SINGLE_LINE+2,fp1))
		{
strcpy(buffer2,buffer);
length= strlen(pfst[0])-1;

if(strncmp(buffer2, pfst[0], length ) == 0 )
	{
	 found2=1;
	}
 if(found2 ==1)
	{
        sprintf(buffer4,"       %s",buffer);
        fputs(buffer4,fp4);
	   if(strstr(buffer,pfet[0]) != NULL)
		{
		found2 = 0;
		count2++;
                }
	}
}

The code works fine when I hard code the string as below

C

if(strncmp(buffer2, "string entered here", length ) == 0 )

But, this won't serve the purpose.. :-(

Thanks in advance,
Faez

Posted 18-Jul-12 21:30pm

Faez Shingeri

Updated 18-Jul-12 21:46pm

v2

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Comments

Richard MacCutchan 19-Jul-12 4:37am

What is the content of pfst[0] and why does pfst need 1500 entries? Stepping through your code with the debugger would likely solve this very quickly.

Faez Shingeri 19-Jul-12 4:49am

Please refer my reply to Prafulla Vedante.
Thanks.

Richard MacCutchan 19-Jul-12 5:14am

This does not answer my question: what is the actual content of pfst[0]? Your code looks unnecessarily complicated for what you are trying to do, all these copy and concatenation operations could be simplified.
Also why are you using the array in pfst and pfet when you only ever compare against the content of the first element in each?

Faez Shingeri 19-Jul-12 5:21am

This variable pfst[][] stores the start range of a section and pfet[][] stores the end range of a section.
For Eg:

This is a test SECTION. //pfst[0] contains this string.
blah blah blah
blah blah blah
blah blah blah
This is a test-EXIT. // pfet[0] containd this string.

Now I want to extract all the contents in the range of pfst[0] and pfet[0]. Similarly pfst[1] & pfet[1] contains another strings.

Hope this answers your query. Do let me know.

Richard MacCutchan 19-Jul-12 5:37am

You have still not answered my question about the actual values you have stored in pfst[0] and pfet[0] and where those strings occur in your input file. Until you can match your stored keywords with the content of your file this will not work.

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Richard MacCutchan · Answer 1 · 2012-07-19T05:49:00

Here is some basic code that works without the necessity of copying buffers all over the place. I am sure you can easily adapt it to your needs. I have had to guess at the actual content of your input file so I have added the file contents below also.

C++

FILE    *fpIn, *fpOut;
char    pfst[10][50];
char    pfet[10][50];
char    buffer[MAX_LEN_SINGLE_LINE];
int     length;
char*   tok;
int     found = 0;

fpIn = fopen("Test.txt", "r");
fpOut = fopen("PerformSectionExtract.txt","w");
    
while(fgets(buffer, MAX_LEN_SINGLE_LINE, fpIn))
{
    if(strncmp(buffer,"PERFORM",7) == 0 )
    {
        fputs("       ", fpOut);
        fputs(buffer, fpOut);
        tok = strtok(buffer + 8, ".\n");
        if (tok != NULL)
        {
            sprintf(pfst[0], "%s SECTION", tok);
            sprintf(pfet[0], "%s -EXIT", tok);
//          i++, j++, p++;
        }
        continue;
    }
    length = strlen(pfst[0]);

    if(strncmp(buffer, pfst[0], length ) == 0 )
    {
        found = 1;
    }
    if (found == 1)
    {
        fputs("       ", fpOut);
        fputs(buffer, fpOut);
        if(strstr(buffer, pfet[0]) != NULL)
        {
            found = 0;
//          count2++;
        }
    }
}

Test.txt

PERFORM test1

blah blah blah
test1 SECTION
test1 1
test1 2
test1 3
test1 -EXIT

ignored stuff 1
ignored stuff 2
ignored stuff 3

PERFORM nextTest
more ignored stuff 1
more ignored stuff 2
more ignored stuff 3

nextTest SECTION
nextTest 1
nextTest 2
nextTest 3
nextTest -EXIT

PerformSectionExtract.txt

PERFORM test1
test1 SECTION
test1 1
test1 2
test1 3
test1 -EXIT
PERFORM nextTest
nextTest SECTION
nextTest 1
nextTest 2
nextTest 3
nextTest -EXIT

PrafullaVedante · Answer 2 · 2012-07-18T22:35:00

Solution 1

Can you share the code where you have assigned string value to

C++

pfst[0]

and

C++

pfet[0]

Posted 18-Jul-12 22:35pm

PrafullaVedante

Comments

Faez Shingeri 19-Jul-12 4:46am

Here you go. I am initially extracting the word after all the PERFORM in the file and then appending "SECTION." to it and storing it in pfst[][] and another append of "-EXIT." to it and storing it in pfet[][]. I now have to extract all the text range between pfst[n] to pfet[n], where n>1000.

<pre>
if(strncmp(buffer2,"PERFORM",7) == 0 )
{

sprintf(buffer1," %s",buffer);
fputs(buffer1,fp2);
strcpy(buffer3, &(buffer2[7]));
tok= strtok (buffer3,".\n");
strcpy(buffer4,buffer3);
if (tok!=NULL)
{
strcat(buffer3," SECTION.");
strcat(buffer4,"-EXIT.");
strcpy(pfst[j++],buffer3);
strcpy(pfet[k++],buffer4);
p++;
}
}
</pre>

How to extract a range of text from a file

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