Reverse a String in C - Solve Segmentation Fault

[carl123]

This is what I came up with but I keep getting segmentation fault whenever I run it in linux. Not sure why. Any help would be appreciated. Thanks

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

int main(int argc, char** argv)
{
    int i, childpid;

    for (i = strlen(argv[1]); i >= 0; i--) {
        if (fork() == 0) {
            printf("%c\n",argv[1][i]);
            break;
        }
    }

    return 0;
}

 

[Orodruin]

i = strlen(argv[1])

This is the position of the terminating null character, not the last character of the string.

 

[carl123]

This is the position of the terminating null character, not the last character of the string.

Thanks for your reply. Pls could you explain further. Not sure what you mean

 

[jedishrfu]

if you have a 10 character string then valid indexes are 0-9 but strlen returns a 10 so your first loop iteration is referencing an out of bounds element of the string which can result in a segmentation fault but not always.

 

[jim mcnamara]

Please note: @CAF123 this post is missing a homework template. Since there are answers it will stay as is.

 

[CAF123]

@jim mcnamara The OP is carl123 and not me (CAF123)

 

[jim mcnamara]

Thanks for the correction. Since the thread died and @CAF123 straightened me out, let's close this thread.