bufargs.c

unix环境高级编程的源代码

#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. */
}