Question

I’m creating a very simple C program call open.c that will either:

1) List the files in the directory that will have the files text stored in an array

I have this code so far but it doesn’t seem to work.

{ }

Answer 1

You need to use argv to compare the command-line arguments with "-ah" and "-ad".

#include <string.h>

if (argc > 2)
{
  if (strcmp (argv[1], "-ah") == 0)
  {
    /* List hidden files */
  }
  else if (strcmp (argv[1], "-ad") == 0)
  {
    /* List files */
  }
  else
  {
    /* Unknown command-line argument */
  }
}
else
{
  /* No command-line arguments */
}

References:

C11 (n1570), § 5.1.2.2.1 Program startup

If they are declared, the parameters to the main function shall obey
the following constraints:

— The value of argc shall be nonnegative.

— argv[argc] shall be a null pointer.

— If the value of argc is
greater than zero, the array members argv[0] through argv[argc-1]
inclusive shall contain pointers to strings, which are given
implementation-defined values by the host environment prior to program
startup. The intent is to supply to the program information determined
prior to program startup from elsewhere in the hosted environment. If
the host environment is not capable of supplying strings with letters
in both uppercase and lowercase, the implementation shall ensure that
the strings are received in lowercase.

— If the value of argc is greater than zero, the string pointed to by argv[0] represents the
program name; argv[0][0] shall be the null character if the program
name is not available from the host environment. If the value of argc
is greater than one, the strings pointed to by argv[1] through
argv[argc-1] represent the program parameters.