Using the search path

Just wondering... does the execl() function use the PATH environment variable? (Or whatever it's called.)

If not, how can I get it to? Would I have to split up the search path string manually, and try each section of it induvidually?

Yes.

The exec() functions with an e in their name let you provide the enviroment variables, including PATH: http://www.opengroup.org/onlinepubs/...ions/exec.html

> f not, how can I get it to? Would I have to split up the search path string manually, and try each section of it induvidually?

You can use the function below

Code:

---

/* Gets the user path and assigns a pointer for each PATH */
int parsePath(char *dirs[])
{
        char *pathEnvVar;
        char *thePath;
        int i;
       
        for (i=0;i<MAX_ARGS;i++)
                dirs[i]=NULL;
        pathEnvVar=(char *)getenv("PATH");
        thePath=(char *)malloc(strlen(pathEnvVar)+1);
        strcpy(thePath,pathEnvVar);
        i=0;
        dirs[i]=thePath;
       
        for(i=1;i<MAX_PATHS;i++)
        {
                if (i==1)
                        dirs[i]=strtok(thePath,":");
                dirs[i]=strtok(NULL,":");
        }
        return 1;
}

---

Why does that function return a value? Why are you casting malloc()? Why aren't you using free()? Why don't you include <string.h>? Why does the comment include "Gets the user path" (should you maybe use getcwd()?)?

Tones of questions...

> Why does that function return a value?
Yes, this is actually unnecessary...Since it expects a pointer as a parameter to change its value

> Why are you casting malloc()?
I did not know the issue in FAQ about the malloc casting when I wrote the code.

> Why aren't you using free()? Why don't you include <string.h>?
This is a function, not the program itself. If somebody wants to use it, (and if he knows a little about C) ,I think, he will be smart enough to include string.h. If I use free, how can I keep the value of *dirs[]

> Why does the comment include "Gets the user path" (should you maybe use getcwd()?)?
Actually the function gets the user PATH and assigns each individual path to a *dirs[] variable. Like *dir[0]="/usr/bin", *dirs[1]="/bin", etc...

And you did not write the whole comment I wrote originally! (Gets the user path...) getcwd returns the user working directory, thes function returns each path found in the PATH variable.

Quote:

---

If I use free, how can I keep the value of *dirs[]

---

You passed dirs[] as a pointer. After you assigned thePath to dirs[] there is no reason to keep thePath's memory around, as it's value will still be available after the function returns. Just somewhere else

> You passed dirs[] as a pointer. After you assigned thePath to dirs[] there is no reason to keep thePath's memory around, as it's value will still be available after the function returns. Just somewhere else

So, this means, even if I free() the memory allocated, it is still possible to use array of *char[]?

Yes exactly, you can free thePath.

*dirs[] is still available because you passed it in from the calling function. *dirs[] doesn't fall out of scope.