Bad address C (command-line interpreter)

Question

Here's my code:

/* myshell program */

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

#define MAX_LENGTH 40
#define TRUE 1

char cmd[MAX_LENGTH];
char args[MAX_LENGTH];

void prompt() {
  printf("%s", "Shell: ");
  scanf("%s", cmd);

  char *line = NULL;  
  size_t linecap = 0; 
  ssize_t linelen;  

  if ((linelen = getline(&line, &linecap, stdin)) > 0) {
    strcpy(args, line);
  }  
}


int main(char *envp[]) {
  while (TRUE) {
    prompt();
    if (fork() == 0) {
        execve(cmd, args, envp);
        perror("execv");
    }
  }
}

Whenever I input (for example) /bin/ls, I get an error stating "Bad address". I have checked cmd and args and made sure that they receive correct values.

`envp[]` is never the first argument to `main()`. It should follow `int argc` and `char **argv`. — Paul Roub, Nov 17 '14 at 15:46
And the `args` parameter to `execve` should be an array of `char *` (like `argv`, etc.), not a single string. The last entry should be `NULL`. — Paul Roub, Nov 17 '14 at 15:51

score 1 · Answer 1 · edited May 23 '17 at 10:26

1

Check the below link: Arguments to main in C

The parameters for main() are int argc and char *argv[]

int main(int argc,char *argv[])

edited May 23 '17 at 10:26

Community

1
1

answered Nov 17 '14 at 15:51

Gopi

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But also http://stackoverflow.com/questions/10321435/is-char-envp-as-a-third-argument-to-main-portable . – Nov 17 '14 at 16:01

Bad address C (command-line interpreter)

1 Answers1