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;

}

---

You could use strchr():

Code:

---

char *column2 = strchr(str, ' ');
if(column2)
  *column2++ = '\0';
else
  column2 = str + strlen(str);
printf("%s\t%s\n", str, column2);

---

*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;
}

---

Quote:

---

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!

Quote:

---

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.

Quote:

---

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.

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?

Quote:

---

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! :D

Quote:

---

Originally Posted by csharp100

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! :D

---

Works good till a point, it prints out the output but then it stops working or other words the program does not exit on its own. I get a windows error and I am using codeblocks with the gcc compiler. Just Tried it on our unix system and I am getting a segmentation fault. Here is my 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);




        }
    while (c != NULL);

    fclose(fP);

    return 0;

}

---

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

Quote:

---

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!

Quote:

---

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;

}

---

Code:

---

do:
  try to read some stuff
  if there is some stuff, then:
      split the string
      display the resulting strings
while there is some stuff.

---

Something like this.

You have to stop RIGHT AWAY. Once you type "char *gpa=", it's too late -- that is not right away any more. You cannot try to process the data if it isn't there.

Quote:

---

Originally Posted by tabstop

You have to stop RIGHT AWAY. Once you type "char *gpa=", it's too late -- that is not right away any more. You cannot try to process the data if it isn't there.

---

Guys I appreciate all the help. I have tried the if statement with !=NULL and ==NULL in it's current location and still getting segmentation fault. I am pulling my hair out with this one.

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




        }
    while (c != NULL);

    fclose(fP);

    return 0;

}

---

I really do not know what to do here. Again, guys I truely appreciate your time with me.

Code:

---

    do {
        c = fgets(str, N ,fP);
        if (c != NULL)
        {
          char *gpa = strchr(str, ' ');
          *gpa++ = '\0';
          printf("%s\t%s\n", str, gpa);
        }
      }while (c != NULL);

---

Or more simply:

Code:

---

while(fgets(str, N, fP))
{
  char *gpa = strchr(str, ' ');
  *gpa++ = '\0';
  printf("%s\t%s\n", str, gpa);
}

---

Quote:

---

Originally Posted by itsme86

Code:

---

    do {
        c = fgets(str, N ,fP);
        if (c != NULL)
        {
          char *gpa = strchr(str, ' ');
          *gpa++ = '\0';
          printf("%s\t%s\n", str, gpa);
        }
      }while (c != NULL);

---

Or more simply:

Code:

---

while(fgets(str, N, fP))
{
  char *gpa = strchr(str, ' ');
  *gpa++ = '\0';
  printf("%s\t%s\n", str, gpa);
}

---

---

Oh thank GAWD! or should I say all of you! Thank you very much!