utils-std

user_group_parse.c (1576B)

// utils-std: Collection of commonly available Unix tools
// SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
// SPDX-License-Identifier: MPL-2.0
#define _POSIX_C_SOURCE 200809L
#include "./user_group_parse.h"
#include <assert.h>
#include <errno.h>
#include <grp.h>    // getgrnam
#include <pwd.h>    // getpwnam
#include <stdio.h>  // fprintf
#include <stdlib.h> // strtoul
#include <string.h> // strerror
int
parse_user(char *str, uid_t *user)
{
	if(str == NULL) return -1;
	if(str[0] == 0) return 0;
	assert(errno == 0);
	char *endptr = NULL;
	unsigned long id = strtoul(str, &endptr, 0);
	if(errno == 0 && endptr != NULL && *endptr == '\0')
	{
		*user = (uid_t)id;
		return 0;
	}
	errno = 0;
	struct passwd *pw = getpwnam(str);
	if(pw == NULL)
	{
		const char *e = strerror(errno);
		if(errno == 0) e = "Entry Not Found";
		fprintf(stderr, "%s: error: Failed to get entry for username '%s': %s\n", argv0, str, e);
		return -1;
	}
	*user = pw->pw_uid;
	return 0;
}
int
parse_group(char *str, gid_t *group)
{
	if(str == NULL) return -1;
	if(str[0] == 0) return 0;
	assert(errno == 0);
	char *endptr = NULL;
	unsigned int id = strtoul(str, &endptr, 0);
	if(errno == 0 && endptr != NULL && *endptr == '\0')
	{
		*group = id;
		return 0;
	}
	errno = 0;
	struct group *gr = getgrnam(str);
	if(gr == NULL)
	{
		const char *e = strerror(errno);
		if(errno == 0) e = "Entry Not Found";
		fprintf(stderr, "%s: error: Failed to get entry for group '%s': %s\n", argv0, str, e);
		return -1;
	}
	*group = gr->gr_gid;
	return 0;
}