Question

I am trying to do simple shell as an exercise to myself. I am writing a function that should find an executable in the PATH, and return a pointer to a string, that contains the full path to executable. Here is what I have so far;

/*bunch of includes here*/

/*
 * Find executable in path, return NULL
 * if can't find.
 */
char *find_executable(char *command)
{
    const char *PATH = getenv("PATH");
    DIR *dp;
    /* get each pathname, and try to find executable in there. */
}

int main(int argc,char *argv[])
{ /* nothing intersting here ...*/
}

I was wondering how should I separate each part of the path, and process these parts in a for loop.

Answer 1

say paths would be separated by ;
You can use strtok function to generate splitted token.
e.g.

char *str = "/foo/a1/b1;/bar/a1/b1"

Now you can use strtok function as

char delims[] = ";"  
char *result = NULL;  
result = strtok( str, delims );  
while( result != NULL ) {  
    dp = result;  
    result = strtok( NULL, delims );   
}