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/*
* Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Hyra nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#define UNKNOWN_USER "unknown"
static char *ucache = NULL;
static int
match_entry(uid_t uid, char *entry)
{
char uidstr[16];
static char *username = NULL;
char *p;
size_t len;
uint8_t row = 0;
if (itoa(uid, uidstr, 10) == NULL) {
return -1;
}
p = strtok(entry, ":");
if (p == NULL) {
return -1;
}
while (p != NULL) {
switch (row) {
case 0:
username = p;
break;
case 2:
/*
* If the user ID matches, we'll cache the
* username.
*/
if (strcmp(uidstr, p) == 0) {
ucache = username;
return 0;
}
break;
}
p = strtok(NULL, ":");
++row;
}
return -1;
}
char *
getlogin(void)
{
FILE *fp;
char entry[256];
int retval;
uid_t uid = getuid();
/* Get the user from the cache */
if (ucache != NULL) {
return ucache;
}
fp = fopen("/etc/passwd", "r");
if (fp == NULL) {
return UNKNOWN_USER;
}
while (fgets(entry, sizeof(entry), fp) != NULL) {
if (match_entry(uid, entry) == 0) {
fclose(fp);
return ucache;
}
}
fclose(fp);
return UNKNOWN_USER;
}
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