search a string in text file in C

**r035198x** · Feb 12 '07, 03:19 PM

Originally posted by agsrinivasan

hi everyone,
i have to search a one word in txt file using C program,..I tried but output not comming right...please give me a flow for that...

i am newbie to C...

regards....

srini

Let's see the code you've written.

**agsrinivasan** · Feb 12 '07, 05:16 PM

Originally posted by r035198x

Let's see the code you've written.

i have read all datas into one buffer....from that I have to search the word...

see my code....

Code:

#include <stdio.h>
#include <stdlib.h>
#include<string.h>

int main () {
  FILE * pFile;
  long lSize;
  char * buffer;
  size_t result;

  pFile = fopen ( "/home/srinivas/Desktop/cl.txt" , "r+" );
  if (pFile==NULL) {fputs ("File error",stderr); exit (1);}

  // obtain file size:
  fseek (pFile , 0 , SEEK_SET);
  lSize = ftell (pFile); printf(" The file size is = %ld",lSize);
  rewind (pFile);

  // allocate memory to contain the whole file:
  buffer = (char*) malloc (sizeof(char)*lSize);
  if (buffer == NULL) {fputs ("Memory error",stderr); exit (2);}

  // copy the file into the buffer:
  result = fread (buffer,1,lSize,pFile);
     
  puts(buffer);
  if (result != lSize) {fputs ("Reading error",stderr); exit (3);}

fclose (pFile);
  free (buffer);
  return 0;
}

**narasip** · Feb 13 '07, 08:09 AM

Hi Srini,

From the code I see that ftell(pFile) will point to the beginning of the file and hence its ouput is 0. This is because you have used SEEK_SET in the fseek func which will bring you to the begining of the file. Try changing SEEK_SET to SEEK_END in the fseek call in the code which moves the cursor to the end of your file. now ftell(pfile) will give you the cursor value which will print the output.

Hope the following code works for you.

Code:

#include <stdio.h>
#include <stdlib.h>
#include<string.h>

int main () {
  FILE * pFile;
  long lSize;
  char * buffer;
  size_t result;

  pFile = fopen ( "/mydir2/narasip/zippy.c" , "r+" );
  if (pFile==NULL) {fputs ("File error",stderr); exit (1);}

  fseek (pFile , 0 , SEEK_END);
  lSize = ftell (pFile); printf(" The file size is = %ld\n",lSize);
  rewind (pFile);

  buffer = (char*) malloc (sizeof(char)*lSize);
  if (buffer == NULL) {fputs ("Memory error",stderr); exit (2);}

  result = fread (buffer,1,lSize,pFile);
  
  puts(buffer);
  if (result != lSize) {fputs ("Reading error",stderr); exit (3);}
  fclose (pFile);
  free (buffer);
  return 0;
}

**agsrinivasan** · Feb 13 '07, 08:47 AM

yeah,
i know that ,but,this is not my question...i have to search one word from this text file..

Thanking you,

srinivas

**kvbreddy** · Feb 13 '07, 08:49 AM

Hi Srinivasan,
What ever the code u have written that works fine for the small input files. Getting entire file content into a char buffer is not good for larger files.
So, better read word by word and search it.

1) Open file.
2) loop until EOF
Read word
If the word is matched
break
loop end

**agsrinivasan** · Feb 13 '07, 12:23 PM

hi...

i had coded like below....

Code:

#include <stdlib.h>
#include<string.h>

int main (void) {
  
	FILE *Input;
	
	long lSize;

        Input = fopen("/home/srinivas/Desktop/cl.txt","r+");

	if (Input ==NULL) {fputs ("File error",stderr); exit (1);}

	fseek (Input ,0 , SEEK_END);
 		
	lSize = ftell (Input); printf(" The file size is = %ld",lSize);

        char string1[24];
        
         
        printf("\n Enter the string you want to search \n");

	gets(string1);

        printf("\n The read string is =%s ",string1 ); 

       //do{
       
        int i=0;
	char string2[24];

	

 /* Read one word for the text file */

	do{
             while( fgets(string2,20,Input) != '\0')
              {
		//string2[i] = fgetc(Input);
                //printf("%c",string2);
		//i++;
	      }
             
	printf("the string2 is %s =",string2);
	printf(" In do loop"); 
            

        if( strcmp(string1,string2) == 0)
         {
		printf(" string successfully searched : string2 = %s",string1);
                 break;
		}

	else
	    {	printf(" string Not found");
		}
         }while(!feof(Input));


            }

I got output Like below....

The file size is = 647579
Enter the string you want to search
SELVA

The read string is =SELVA the string2 is \uffff\u04bf\uf fff\uffff\uffff \uffff,\uffff\u ffff\uffff\u04b f\uffff\uffffSE LVA = In do loop string Not foundsuse:

wheather my code is correct???

for searching a word in a file....

**kvbreddy** · Feb 13 '07, 03:52 PM

This is ur code partly modified....

Code:

        rewind(Input);
       /* Read one word for the text file */

         while(!feof(Input))
         {
            fscanf(Input, "%s", string2);

            printf("The string2 is: %s\n",string2);
            
            if ( strcmp(string1,string2) == 0)
            {
                printf("String successfully searched\n");
                break;
            }
        }
        if (feof(Input))
        {
            printf("string search failed\n");
        }

finally close the file.

vijay

**agsrinivasan** · Feb 13 '07, 05:16 PM

Originally posted by kvbreddy

This is ur code partly modified....

rewind(Input);
/* Read one word for the text file */

while(!feof(Inp ut))
{
fscanf(Input, "%s", string2);

printf("The string2 is: %s\n",string2);

if ( strcmp(string1, string2) == 0)
{
printf("String successfully searched\n");
break;
}
}
if (feof(Input))
{
printf("string search failed\n");
}

finally close the file.

vijay

sorry vijay,
This file not working ,it was printing all names in the file...

i want to search One seperate word like "ABC" in text file...

Thanks,

srini...

**kvbreddy** · Feb 14 '07, 07:10 AM

no..no.. it's working. I have tested this.
can u post ur code again... i will see...

Originally posted by agsrinivasan

sorry vijay,
This file not working ,it was printing all names in the file...

i want to search One seperate word like "ABC" in text file...

Thanks,

srini...

**agsrinivasan** · Feb 15 '07, 05:01 AM

Originally posted by kvbreddy

no..no.. it's working. I have tested this.
can u post ur code again... i will see...

I had tried one more method ...it is working successfully...

see the code....

Code:

#include <stdio.h>
#include <stdlib.h>
#include<string.h>

int main (void) {
  
	FILE *Input;
	
	long lSize;

         size_t result;

        char *buffer;

        Input = fopen("/home/srinivas/Desktop/cl.txt","r+");
	printf("Input value: %d\n",Input);

	if (Input ==NULL) {fputs ("File error",stderr); exit (1);}

	fseek (Input ,0 , SEEK_END);
 		
	lSize = ftell (Input); printf(" The file size is = %ld\n",lSize);
        
        rewind (Input);

	  // allocate memory to contain the whole file:
	  buffer = (char*) malloc (sizeof(char)*lSize);
	  if (buffer == NULL) {fputs ("Memory error",stderr); exit (2);}

	  // copy the file into the buffer:
	  result = fread (buffer,1,lSize,Input);

	   long i,j,len,z;

          char string1[20];
 
          printf(" Enter the Name you want to search \n");

           gets(string1);

          len = strlen(string1);

          //printf("The length of the string = %d ",len);

           char string2[20];

          // char *compare;
         
	fseek (Input ,0 , SEEK_SET);
       

	for(i=0;i <lSize ; i++)
	{
	  	//printf("%c ,%c \n ",string1[0],buffer[i]);
		if(string1[0] == buffer[i]){
               // printf("Inside if Loop\n");
	         for(z=0, j=i ;j < i+len  ;j++)
		{
                      
                   // printf("Inside for Loop\n");
	            string2[z] = buffer[j];
                    z++;
                  }
       			
         //  printf("The length of the string2= %d,%s ",strlen(string2),string2);

              if(strcmp(string1,string2) == 0)
    				{
        				printf("string successfully searched\n ");
     				}      
                   
               			//else
                                  //  printf("string Not found\n");
		}
 }
  
   

}

**agsrinivasan** · Feb 15 '07, 05:31 AM

hi...
I have text file.one part of a file ..i given below..

7. LPA.SR 36917/2006 M/S.V.SELVARAJ
D. JAYASINGH
V.S.MANIMEKALAI
and
MP.SR 67318/2006
FOR EXTENSION OF TIME
~~~~~~~~~~~~~~~ ~~~~~~

8. OSA.323/2006 M/S.AIYAR AND DOLIA M/S.RAM AND RAJAN & ASSOCTS.
V. KALYANARAMAN FOR R1
R2 OFFICIAL LIQUIDTOR
R3 TIMES GURANTEE LTD MUMBAI - 1
and
OSA.324/2006
MP.1/2006
MP.2/2006
FOR DIRECTION
~~~~~~~~~~~~~

9. (NOT READY IN NOTICE)
WA.1246/1998 M/S K.BALASUBRAMANI AN MR.M.V.VENKATAS ESHAN FOR R1
and
CMP.13730/1998
WA.1247/1998 MR.A.FATHIMANAT HAN MR.M.V.VENKATAS ESHAN FOR R3
and
CMP.13731/1998
FOR JUDGMENT
~~~~~~~~~~~~

Now what my next plan is ...I have to search one string..that was done already...

I have to put tags for eg..$$ into before starting of serial No 7..and also put tag into befor serial no 8...

------------------------------------------------------------------------------------------------------------
for eg....
$$ 7. LPA.SR 36917/2006 M/S.V.SELVARAJ
D. JAYASINGH
V.S.MANIMEKALAI
and
MP.SR 67318/2006
FOR EXTENSION OF TIME
~~~~~~~~~~~~~~~ ~~~~~~ $$

8. OSA.323/2006 M/S.AIYAR AND DOLIA M/S.RAM

-------------------------------------------------------------------------------------------------------------
This is my requirement...

give me suggestions

**friendjin** · Feb 15 '07, 11:21 PM

try: strstr

Code:

while(!file.eof())
{
setline(file,&line);
strstr(line, "ABC")
}

look up strstr command

**friendjin** · Feb 15 '07, 11:29 PM

otherwise you can do a simple way but not good. but i am sure it is working.

Code:

char SearchName[4]= "ABV";
int time;
for (time=0, time< 1000, time++)  // time value depends the size of the file
{
scanf ("%c", &buffer[time]);
while(SearchName[0]==buffer[time])
						
{   
							time++;
							while(SearchName[1]==buffer[time])
							
{
								time++;
								while(SearchName[2]==buffer[time])
								{
															//search successful.		
								}

}

}
}

search a string in text file in C

search a string in text file in C

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