Thread: Split string in sequential file to add a tabstop between the strings...

Hey everyone, I have the following code and trying to figure out a way to split the string, "Brown 3.75, Jones 4.00, etc. and then add a tabstop between them for printing. Is there a simple command or way to do this? Thanks in advance!

Code:

#include <stdio.h>
#include <stdlib.h>
#define N 100

int main()
{
    FILE *fP;
    char str[N], *c;


    if ((fP = fopen("names.dat", "r")) == NULL)
    {
        printf("%s not opened", "names.dat");
        exit(EXIT_FAILURE);
    }
    do {
        c = fgets(str, N ,fP);
        if (c != NULL)

            printf("%s\n", str);
        }
    while (c != NULL);

    fclose(fP);

    return 0;

}

*scanf with formatspecifier %s will split for you:

Code:

#include <stdio.h>
#include <stdlib.h>
#define N 100

int main()
{
    FILE *fP;
    char str[N], *c;


    if ((fP = fopen("names.dat", "r")) == NULL)
    {
        printf("%s not opened", "names.dat");
        exit(EXIT_FAILURE);
    }

    while( 1==fscanf(fP,"%99s",str) )
      printf("%s\t",str);

    fclose(fP);

    return 0;
}

Originally Posted by BillyTKid

*scanf with formatspecifier %s will split for you:

Code:

#include <stdio.h>
#include <stdlib.h>
#define N 100

int main()
{
    FILE *fP;
    char str[N], *c;


    if ((fP = fopen("names.dat", "r")) == NULL)
    {
        printf("%s not opened", "names.dat");
        exit(EXIT_FAILURE);
    }

    while( 1==fscanf(fP,"%99s",str) )
      printf("%s\t",str);

    fclose(fP);

    return 0;
}

Thanks, but I have to use fgets. That was my first thought as well.

If you have to use fgets, then use sscanf on the string returned!

Originally Posted by rags_to_riches

If you have to use fgets, then use sscanf on the string returned!

Now I am getting just one line of my .dat file and it happens to be the last one. Did I miss something?

You're probably overwriting each time. Either print it out inside the loop, or save it somewhere.

Originally Posted by BillyTKid

*scanf with formatspecifier %s will split for you:

Code:

#include <stdio.h>
#include <stdlib.h>
#define N 100

int main()
{
    FILE *fP;
    char str[N], *c;


    if ((fP = fopen("names.dat", "r")) == NULL)
    {
        printf("%s not opened", "names.dat");
        exit(EXIT_FAILURE);
    }

    while( 1==fscanf(fP,"%99s",str) )
      printf("%s\t",str);

    fclose(fP);

    return 0;
}

I really like what you did here, but can you tell me how I would get this print out?
Brown 3.75
Jones 4.00

Basically I need to have a "name <tab> GPA" then a new line with the same.

Originally Posted by itsme86

Dude, the strchr() solution is faster/cleaner. If you omit the error checking just do this:

Code:

char *gpa = strchr(str, ' ');
*gpa++ = '\0';
printf("%s\t%s\n", str, gpa);

Is there a reason you don't want to use it?

Not at all, I am trying that as we speak. Just trying to understand it that is all. I really appreciate your help. Thank you!

When c is NULL you need to stop RIGHT NOW, not "after this loop is finished".

Originally Posted by tabstop

When c is NULL you need to stop RIGHT NOW, not "after this loop is finished".

Could you be a bit more specific? I placed an if statement within the do/while loop after the print statement:

Code:

if (c = NULL)
break:

What it did was only print out one line and tat was the first line of my .dat file.

Assignment is not equality:

if(c == NULL) /* is it NULL? */

if(c = NULL) /* assign NULL to C */

Normally an IDE would warn if you use assignment in a boolean context. Turn up your warning level!

Originally Posted by whiteflags

Assignment is not equality:

if(c == NULL) /* is it NULL? */

if(c = NULL) /* assign NULL to C */

Normally an IDE would warn if you use assignment in a boolean context. Turn up your warning level!

Dang! Another segmentation fault. The latest code:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define N 100

int main()
{
    FILE *fP;
    char str[N], *c;
    char *gpa = strchr(str, ' ');


    if ((fP = fopen("names.dat", "r")) == NULL)
    {
        printf("%s not opened", "names.dat");
        exit(EXIT_FAILURE);
    }
    do {
        c = fgets(str, N ,fP);
        char *gpa = strchr(str, ' ');
        *gpa++ = '\0';
        printf("%s\t%s\n", str, gpa);
        if (c == NULL)
        break;



        }
    while (c != NULL);

    fclose(fP);

    return 0;

}