write a function to retern char **

Hi All, am trying to write a function that returns a pointer to a character pointer
something of the form

Code:

---

char  ** get_command(int loc);

---

but I get an error at the prototype definition that * is unexpected!
Is it that functions in C cannot return char ** type or do i need to define my function differently?

Help is highly appreciated.
sismail

In C, we can declare function with return type char **.
It won't give the error if you returned the pointer to a character pointer in a function.
I just tried some program. It won't be a useful code for you. But in that it return char **. it doesn't give any error.

Code:

---

#include<stdio.h>
char **func(char **a);

int main(int argc, char **argv)
{
char **av=func(argv);
printf("%s\n",av[0]);
return 0;
}
char **func(char **a)
{
        return a;
}

---

I think the problem may be in your program. Post your code . Then only, I can solve your problem.

I am using GCC V4.1.2

Code:

---

char ** getcommand(int loc);
This prototype says no error

---

As ganesh said problem may be in your code, other wise paste the error message here!
but Im know for sure that C can return pointer to pointer to char

Here is the code .. By the way am using Minix cc compiler. Every thing was working just fine untill i added the function

Code:

---

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/stat.h>

extern char **getline();
char **getNextCommand(Char **args,int order,int npipes);/* error at this line */
int main() {
  int i,j, npipes,status;
  pid_t pid , npid;
  char **args, **new_args, **args_temp;
  int * pipe_fd;
  while(1) {
      /* Some code here ... */
    if( (args = getNextCommand(args,j,npipes)) == NULL){
          fprintf(stderr, "Un expected error\n");
        exit(2);
      }
  /* Some code here ... */
}

char ** getNextCommand(Char **args,int order,int npipes)
{
        int j,i,count;
        char ** new_args;
        if(order == 0){
                j =0;
                for( i=0;args[i] != NULL && strcmp(args[i],"|") != 0 ; i++)
                        new_args[j++] = args[i];
                new_args[i] = NULL;       
        }
        else{
                count = 0; i =0; j =0;
                while(args[i] != NULL && strcmp(args[i] , "|") == 0){
                        count ++; i++;
                }/* end: while*/
               
                if(args[i] == NULL){
                                    fprintf(stderr, "command not properly formatted");
                                    return NULL;}
                while(strcmp(args[i], "|") != 0 && args[i] != NULL){
                        new_args[j++] = args[i++];
                }/* end: while */
                new_args[j] =NULL;       
        }/* end else */

        return new_args;
}/* end getNextCommand */

---

It may be the problem.
I think you are using character type as Char rather than char.
while declaring and defining getNextCommand function

And I am using cc compiler.

This code works fine for me

Code:

---

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/stat.h>

extern char **getline();
char **getNextCommand(char **args,int order,int npipes);/* error at this line */
int main() {
  int i,j, npipes,status;
  pid_t pid , npid;
  char **args, **new_args, **args_temp;
  int * pipe_fd;
  while(1) {
      /* Some code here ... */
    if( (args = getNextCommand(args,j,npipes)) == NULL){
          fprintf(stderr, "Un expected error\n");
        exit(2);
      }
  /* Some code here ... */
  }
}

char ** getNextCommand(char **args,int order,int npipes)
{
        int j,i,count;
        char ** new_args;
        if(order == 0){
                j =0;
                for( i=0;args[i] != NULL && strcmp(args[i],"|") != 0 ; i++)
                        new_args[j++] = args[i];
                new_args[i] = NULL;
        }
        else{
                count = 0; i =0; j =0;
                while(args[i] != NULL && strcmp(args[i] , "|") == 0){
                        count ++; i++;
                }/* end: while*/

                if(args[i] == NULL){
                                    fprintf(stderr, "command not properly formatted");
                                    return NULL;}
                while(strcmp(args[i], "|") != 0 && args[i] != NULL){
                        new_args[j++] = args[i++];
                }/* end: while */
                new_args[j] =NULL;
        }/* end else */

        return new_args;
}/* end getNextCommand */

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I think you must change Char as char.
I run the command like
$ a.out ls| find and it was working fine!! :)

Thanks a lot that was the problem. Changed Char to char and all is good.
Appreciate the help.