Read file in C

[chikhalepankaj]

Hi guys,

I have a problem in reading a file content which r in tab separated value
formate eg.
MODULE AD0 AD1 AD2 AD3 AD4 AD5 AD6 AD7
4011 +001.10 -001.00 +000.11 +000.11 -001.11 ~ ~ ~
4012 +001.10 -001.00 +000.11 +000.11 -001.11 ~ ~ ~
4013 +001.10 -001.00 +000.11 +000.11 -001.11 ~ ~ ~
4014
from above table i have to read 1st column like.
MODULE
4011
4012
4013

i have tried some code which is read the content & print it in desired formate
BUT THE MAIN PROBLEM IS WHEN I TRY TO STORE IN CHAR * ARRAY
IT GET STORE NEXT VALUE WHICH IS POINTED BY FILE POINTER

Code on Linux system:

#include<stdio.h>
#include<string.h>
#include<fcntl.h>
#include<sys/stat.h>
 
#define LINE_LENGTH  200    
#define ESC          27
 
   int i,j,l = 0;
 
   main()                                                         
   {
 
        FILE *fp;                                                                               
 
        char list[LINE_LENGTH];
 
        char *choices[6];
 
        int num;        
 
       fp=fopen("../pankaj/c1.txt","r");
 
       printf("\n Enter the No.of Modules :");
 
        scanf("%d",&num);
 
        system("clear");  
 
        int k =0;
 
        while(fgets(list,LINE_LENGTH,fp) &&  num >= 0 )
         {
 
                  char *result1=NULL;
                  char *sptr=list;
              //   result1 = strtok_r(list,"\n",&sptr);
                  result1=strsep(&sptr,"\n");
 
                  while(result1!=NULL)            
                    { 
                     int len;
                     len  =strlen(result1);
 
                     result1[len]='\0';
 
                     choices[k]=result1;
 
 
                     printf("\n%s ",result1);    
                     printf(" %s\n", choices[k]);     
 
 
                     result1= strtok(NULL,"\n");
 
                         k=k+1;
                   }                        
 
 
 
                     num--;          
 
         }
 
 
        for(l=0;l<=5;l++)
            {
             printf("\n%s\n",choices[l]) ; 
            }
 
    fclose(fp);
 
  }
 

In above code the statement printf("\n%s ",result1);
printf(" %s\n", choices[k]);

gives desired output but when i try to store in char * choices[ ]
and then try to print out of while loop it get printed value as ......
4014
which is not a desired o/p

So my question is why this array ptr stores some other value??????????
plz help me I m new in C so if is there any mistake plz forgive me..............

I HOPE u will Reply me as soon as possible......

[mac11]

Your getting strange results because your only pointing to list[] with choices[]. The next time through the loop list changes (the contents of list are changed) but the pointers in choices[] still point to the same location from list[] (but that location now contains something else).

Try copying from list[] to choices[] - but you will first have to give choices[] some memory. Either use malloc() to allocate on the fly under choices[k] or just declare choices with memory to begin with (choices[6][128] - or whatever is enough), then use strcpy() to copy the contents of list[] before they change