split a commandline into command and paramters

commandline_param.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <ctype.h>
#include <string.h>

typedef struct
{
  char *command;
  char *parameter1;
  char *parameter2;
} tCommandLine;

void ToLower(char *str) {
  int i = 0;
  for (i=0; str[i]; i++) {
    str[i] = tolower(str[i]);
  }
}

// Function to get the nth parameter word of a string, splitting on spaces
void get_param(char * str, char * value, int n) {
  int start = 0, length = 0, m = 0;

printf("Searching for %dth parameter of [%s]\n", n, str);

  for (int i=0; i<(strlen(str)); i++) {
    if ( str[i] == ' ' ) {
      m++;
      if ( m == ( n - 1 ) ) {
        start = i+1;
      } else if ( m == n ) {
        length = i - start;
        break;
      }
    }
  }

  // Voor de laatste parameter
  if ( length == 0 ) {
    length = strlen(str) - start;
  }

  // Veiligheid, we mogen niet langer kopieren dan we ruimte hebben
  if ( length > sizeof(value) ) {
    length = sizeof(value);
  }

printf("start = %d, lenght = %d\n", start, length);
  if ( length > 0 ) {
    memcpy(value, &str[start], length);
  }
  return;
}

int main ( int argc, const char * argv[]) {
  char *input = "one two three four five";
  tCommandLine cmd;
  cmd.command = malloc(8);
  cmd.parameter1 = malloc(8);
  cmd.parameter2 = malloc(8);
  get_param(input, cmd.command, 1 );
  get_param(input, cmd.parameter1, 2 );
  get_param(input, cmd.parameter2, 3 );

  printf("Command = [%s]\n", cmd.command);
  printf("Param 1 = [%s]\n", cmd.parameter1);
  printf("Param 2 = [%s]\n", cmd.parameter2);
  return 0;
}