Thread: seg with args

Here some things to look over:

Code:

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

int main(int argc, char *argv[])
{
  char mychar;
  if (argc == 2)
  {
    printf ("argv[1] is %s\n", argv[1]);
    if (strncmp(argv[1], "-n", 2) == 0)
    {
      mychar = argv[1][2];
      if (mychar != '\0')
        printf ("found char as %c\n", mychar);
    }
  }
  return(0);
}

/*
 * When invoked with ./a.exe -nZ
 argv[1] is -nZ
 found char as Z
 *
 */

And another sample to help you understand the layout of the command line args as they sit in memory:

Code:

#include <stdio.h>

int main(int argc, char *argv[])
{
  int i, j;
  for (i = 0; i < argc; i++)
    for (j = 0; argv[i][j]; j++)
      printf ("argv[%d][%d] is %c\n", i, j, argv[i][j]);
  return(0);
}

/*
 * When invoked with a.exe -nZ
 argv[0][0] is E
 argv[0][1] is :
 argv[0][2] is \
 argv[0][3] is a
 argv[0][4] is .
 argv[0][5] is e
 argv[0][6] is x
 argv[0][7] is e
 argv[1][0] is -
 argv[1][1] is n
 argv[1][2] is Z
 *
 */