bufargs.c

unix高级编程源代码.<<unix高级编程>>

#include	"ourhdr.h"

#define	MAXARGC		50	/* max number of arguments in buf */
#define	WHITE	" \t\n"	/* white space for tokenizing arguments */

/* buf[] contains white-space separated arguments.  We convert it
 * to an argv[] style array of pointers, and call the user's
 * function (*optfunc)() to process the argv[] array.
 * We return -1 to the caller if there's a problem parsing buf,
 * else we return whatever optfunc() returns.  Note that user's
 * buf[] array is modified (nulls placed after each token). */

int
buf_args(char *buf, int (*optfunc)(int, char **))
{
	char	*ptr, *argv[MAXARGC];
	int		argc;

	if (strtok(buf, WHITE) == NULL)		/* an argv[0] is required */
		return(-1);
	argv[argc = 0] = buf;

	while ( (ptr = strtok(NULL, WHITE)) != NULL) {
		if (++argc >= MAXARGC-1)	/* -1 for room for NULL at end */
			return(-1);
		argv[argc] = ptr;
	}
	argv[++argc] = NULL;

	return( (*optfunc)(argc, argv) );
			/* Since argv[] pointers point into the user's buf[],
			   user's function can just copy the pointers, even
			   though argv[] array will disappear on return. */
}