Main function of C

main.c

#include <assert.h>
#include <stdio.h>

/*
 * 5.1.2.2.1 Program startup
 * N1548
 */
int main(int argc, char *argv[]) {
  // The value of argc shall be nonnegative.
  assert(argc >= 0);
  // argv[argc] shall be a null pointer.
  assert(argv[argc] == NULL);
  /*
   * 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.
   */
  for (int i = 0; i < argc; i++) {
    printf("argv[%d]: %s\n", i, argv[i]);
  }
  /*
   * 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.
   */
  if (argc > 0) {
    if (argv[0][0] != '\0') {
      printf("program name: %s\n", argv[0]);
    }

  }
  if (argc > 0) {
    for (int i = 1; i < argc; i++) {
      printf("program parameter: %s\n", argv[i]);
    }
  }
  /*
   * The parameters argc and argv and the strings pointed to by the argv array shall
   * be modifiable by the program, and retain their last-stored values between program
   * startup and program termination.
   */
  if (argc > 0) {
    if (argv[0][0] != '\0') {
      argv[0][0] = 'a';
    }
  }
  if (argc > 1) {
    argc = 1;
  }
}