Thread: Parsing a comma separated string that has spaces while IGNORING the spaces...

Hello, I'm having issues trying to parse a comma separated string...I can't seem to get past the spaces

I'm simply trying to parse a string that is as follows:

Code:

Date,Subject,Start Time,End Time,Location

Basically I want to end up with an array of strings containing each of the items that were separated by commas.

Here is my program...

Code:

int
main(void)
{
        FILE *inp;
        char *line;
        int N = 10, M = 10;
        int linemax  = 256;
        int i = 0, j = 0;
        char **stringarray;

        line = (char *)malloc(sizeof(char) *N);
        stringarray = (char**)calloc(sizeof(char**), M);

        inp = fopen("appts.csv","r");

        fgets(line, linemax, inp);


        printf("%s\n",line);

        stringarray[0] = strtok(line, ",");
        stringarray[1] = strtok(NULL, ",");
        stringarray[2] = strtok(NULL, ",");
        stringarray[3] = strtok(NULL, ",");
        stringarray[4] = strtok(NULL, ",");

        for(j; j < 6; j++) {
                printf("%s\n", stringarray[j]);
        }



        return(0);
}

This is my output...

Code:

$ a.out
Date,Subject,Start Time,End Time,Location

Date
Subject
Sta             )

Segmentation fault (core dumped)

How can I parse the string by commas? I know I should really be using strtok in a loop, but I'm trying to parse in the most simplest way possible before attempting to do anything more complex since I'm a beginner programmer.

Thanks in advance.

Check out fscanf, or fgets + sscanf

The issue isn't with strtok(), altho' there's a better way to go about it, but with the storage allocation; cause of the segv at runtime.

Code:

line = (char *)malloc(sizeof(char) *N);  /* line points to an array that can hold only 10 characters */
...
fgets(line, linemax, inp);  /* tries to read 255 chars from inp into the array pointed to be line?? */

Ok, so I have a better idea of what I should be doing...trying to not make things too complex but I still seem to be getting a seg fault... >_<

Any tips for what I should change?

New stuff I did is in red.

Code:

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

int
main(void)
{
        FILE *inp;
        char *line;
        int N = 10, M = 10;
        int linemax  = 256;
        int i = 0, j = 0;
        char **stringarray;
        int a = 0, b = 0, c = 0, length;


        line = (char *)malloc(sizeof(char) *N);
        stringarray = (char**)calloc(sizeof(char**), M);

        inp = fopen("appts.csv","r");

        fgets(line, linemax, inp);


        printf("%s\n",line);


        length = strlen(line);

        while(line[a] != line[length]) {

                if(line[a] == ',') {
                        b++;
                } else {
                        stringarray[b][c] = line[a];
                        c++;
                }
                a++;
        }


        for(j; j < 6; j++) {
                printf("%s\n", stringarray[j]);
        }



        return(0);
}

Your segfault won't go away until you fix your storage allocations.
Why not go for static allocation instead of dynamic as you are a beginner.
Once the code is working you can switch to dynamic allocation.

Ok I did away with the dynamic arrays for now. I don't seg fault anymore, but there seems to be some unexplainable logical error somewhere that I can't find!

The logic seems okay to me, but I'm guessing there's something I'm missing.

This is the output that I want:

Code:

$ a.out
Date,Subject,Start Time,End Time,Location

Date
Subject
Start Time
End Time
Location

$

But this is the output that I'm getting:

Code:

$ a.out
Date,Subject,Start Time,End Time,Location

Date





$

What's going on here..?

Here's my code, with new changes in red.

Code:

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

int
main(void)
{
        FILE *inp;
        char line[100];
        int linemax  = 256;
        int i = 0, j = 0;
        char stringarray[100][100];
        int a = 0, b = 0, c = 0, length, count = 0;

        inp = fopen("appts.csv","r");

        fgets(line, linemax, inp);


        printf("%s\n",line);


        length = strlen(line);

        while(count != length) {

                if(line[a] == ',') {
                        b++;
                } else {
                        stringarray[b][c] = line[a];
                        c++;
                }
                a++;
                count++;
        }


        for(j; j < 6; j++) {
                printf("%s\n", stringarray[j]);
        }



        return(0);
}

Now revert back to the strtok() instead of the new code in red.