initgroups.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 50 行

/*	initgroups.c	4.4	83/06/17	*/

/*
 * initgroups
 */
#include <stdio.h>
#include <sys/param.h>
#include <grp.h>

struct group *getgrent();

initgroups(uname, agroup)
	char *uname;
	int agroup;
{
	int groups[NGROUPS], ngroups = 0;
	register struct group *grp;
	register int i, j, found;

	if (agroup >= 0)
		groups[ngroups++] = agroup;
	setgrent();
	while (grp = getgrent()) {
		if (grp->gr_gid == agroup)
			continue;
		for (i = 0; grp->gr_mem[i]; i++){
			if (!strcmp(grp->gr_mem[i], uname)) {
				if (ngroups == NGROUPS) {
fprintf(stderr, "initgroups: %s is in too many groups\n", uname);
					goto toomany;
				}
				found = 0;
				for(j = 0; j < ngroups; j++){
					if(groups[j] == grp->gr_gid)
						found++; /*GROK!*/
				}
				if(!found)
					groups[ngroups++] = grp->gr_gid;
			}
		}
	}
toomany:
	endgrent();
	if (setgroups(ngroups, groups) < 0) {
		perror("setgroups");
		return (1);
	}
	return (0);
}