/* argvwords.c - collect argv array from command line words
 * 2009.09.24 Neal Nelson
 *
 * This version actually keeps adding words to the argv line after line
 * up to the allocated size of the argv array. The program handles multiple
 * lines and multiple words on a line. End with EOF at the beginning of a line.
 *
 * I can probably improve this by scanning the word directly into the
 * argv array instead of into an intermediate word array.
 */

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

#define MAXLINE 80
#define MAXWORDS 3

char *getArg(char *buf, char *word);
void *malloc();            /* should probably use calloc in general */

main()
{ char buf[MAXLINE];       /* fgets reads only MAXLINE-1 */
  char word[MAXLINE+1];    /* add one for zero at end of line */
  char *argv[MAXWORDS+1];  /* add one for zero at end of argv array */
  char *p;
  int argc = 0;
  int i;

  /* collect command lines until EOF (^d) at begin of line */
  while (fgets(buf, MAXLINE, stdin) != NULL)
  { /* fill up argv */
    for (p = buf; (p = getArg(p,word)) != NULL && argc < MAXWORDS; )
    { printf ("  %s\n", word);
      /* now put word in argv[argc++] */
      argv[argc] = (char *)malloc(strlen(word) + 1);
      strcpy(argv[argc++],word);
    }
    argv[argc] = (char *)0;

    /* now print out argv */
    printf("The words in argv (max %d) ...\n",MAXWORDS);
    for (i = 0; i < argc; i++)
    { printf("%s\n",argv[i]);
    }
  }

}

char* getArg(char *buf, char *word)
{ char *p;
  int i;

  for (p = buf; isspace(*p); p++);                 /* skip leading spaces */
  for (i = 0; !isspace(*p) && *p != '\0'; p++)     /* get next word */
  { word[i++] = *p;
  }
  word[i] = '\0';
  if (i == 0) return NULL; else return p;
}