Thread: How replace a string of a specific person in a file

I think you have to write some logic.

1. This isn't the 80s, stop using conio.h and whatever broke compiler you have and Get a modern compiler
2. Using text file IO for this is a bad decision, take a look at Binary File IO
3. The best way to do this is to use a DB, however if you are doing a roll your own format, I would suggest a lookup table at the end or beginning of the file (or a separate file all together) that has the student mapped to a entry number. You would read this in at the beginning, then advance to the appropriate place on the file based on your look up table results, and modify the structure from there.

The structure use only pointer to character.

Code:

typedef struct record {
  char *fname;
  char *lname;
  int code;
} information;

First, the function strdup is unknown for me, but i assume that you want to copy the string (strcpy/strncpy).
But this will not work, because there are only pointers in the structure. There are no space for characters.


Second: if the input file isn't open, you return without a value, but the main function should return a integer.


Third: you don't check the output file.

Code:

…
    ufile= fopen("update.txt","w");


    fprintf(ufile,"First Name     Last Name     ID     Status     Time Arrived\n");
    for (i = 0; i < x; i++) {
        fprintf(ufile,"%-15s%-14s%2d%12s ",(array[i].fname), (array[i].lname), (array[i].code), status);
        fprintf(ufile,"%16s",(buf)); 
    }//end of for loop
    fclose(ufile);
…

The indentation is also a little bit broken.
Update your code and post it here in code-tags.