143 lines
3.2 KiB
C
143 lines
3.2 KiB
C
/* getpwent(), getpwuid(), getpwnam() - password file routines
|
|
*
|
|
* Author: Kees J. Bot
|
|
* 31 Jan 1994
|
|
*/
|
|
#define nil 0
|
|
#define open _open
|
|
#define fcntl _fcntl
|
|
#define read _read
|
|
#define close _close
|
|
#include <sys/types.h>
|
|
#include <pwd.h>
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <fcntl.h>
|
|
|
|
#define arraysize(a) (sizeof(a) / sizeof((a)[0]))
|
|
#define arraylimit(a) ((a) + arraysize(a))
|
|
|
|
static char PASSWD[]= "/etc/passwd"; /* The password file. */
|
|
static const char *pwfile; /* Current password file. */
|
|
|
|
static char buf[1024]; /* Read buffer. */
|
|
static char pwline[256]; /* One line from the password file. */
|
|
static struct passwd entry; /* Entry to fill and return. */
|
|
static int pwfd= -1; /* Filedescriptor to the file. */
|
|
static char *bufptr; /* Place in buf. */
|
|
static ssize_t buflen= 0; /* Remaining characters in buf. */
|
|
static char *lineptr; /* Place in the line. */
|
|
|
|
void endpwent(void)
|
|
/* Close the password file. */
|
|
{
|
|
if (pwfd >= 0) {
|
|
(void) close(pwfd);
|
|
pwfd= -1;
|
|
buflen= 0;
|
|
}
|
|
}
|
|
|
|
int setpwent(void)
|
|
/* Open the password file. */
|
|
{
|
|
if (pwfd >= 0) endpwent();
|
|
|
|
if (pwfile == nil) pwfile= PASSWD;
|
|
|
|
if ((pwfd= open(pwfile, O_RDONLY)) < 0) return -1;
|
|
(void) fcntl(pwfd, F_SETFD, fcntl(pwfd, F_GETFD) | FD_CLOEXEC);
|
|
return 0;
|
|
}
|
|
|
|
void setpwfile(const char *file)
|
|
/* Prepare for reading an alternate password file. */
|
|
{
|
|
endpwent();
|
|
pwfile= file;
|
|
}
|
|
|
|
static int getline(void)
|
|
/* Get one line from the password file, return 0 if bad or EOF. */
|
|
{
|
|
lineptr= pwline;
|
|
|
|
do {
|
|
if (buflen == 0) {
|
|
if ((buflen= read(pwfd, buf, sizeof(buf))) <= 0)
|
|
return 0;
|
|
bufptr= buf;
|
|
}
|
|
|
|
if (lineptr == arraylimit(pwline)) return 0;
|
|
buflen--;
|
|
} while ((*lineptr++ = *bufptr++) != '\n');
|
|
|
|
lineptr= pwline;
|
|
return 1;
|
|
}
|
|
|
|
static char *scan_colon(void)
|
|
/* Scan for a field separator in a line, return the start of the field. */
|
|
{
|
|
char *field= lineptr;
|
|
char *last;
|
|
|
|
for (;;) {
|
|
last= lineptr;
|
|
if (*lineptr == 0) return nil;
|
|
if (*lineptr == '\n') break;
|
|
if (*lineptr++ == ':') break;
|
|
}
|
|
*last= 0;
|
|
return field;
|
|
}
|
|
|
|
struct passwd *getpwent(void)
|
|
/* Read one entry from the password file. */
|
|
{
|
|
char *p;
|
|
|
|
/* Open the file if not yet open. */
|
|
if (pwfd < 0 && setpwent() < 0) return nil;
|
|
|
|
/* Until a good line is read. */
|
|
for (;;) {
|
|
if (!getline()) return nil; /* EOF or corrupt. */
|
|
|
|
if ((entry.pw_name= scan_colon()) == nil) continue;
|
|
if ((entry.pw_passwd= scan_colon()) == nil) continue;
|
|
if ((p= scan_colon()) == nil) continue;
|
|
entry.pw_uid= strtol(p, nil, 0);
|
|
if ((p= scan_colon()) == nil) continue;
|
|
entry.pw_gid= strtol(p, nil, 0);
|
|
if ((entry.pw_gecos= scan_colon()) == nil) continue;
|
|
if ((entry.pw_dir= scan_colon()) == nil) continue;
|
|
if ((entry.pw_shell= scan_colon()) == nil) continue;
|
|
|
|
if (*lineptr == 0) return &entry;
|
|
}
|
|
}
|
|
|
|
struct passwd *getpwuid(_mnx_Uid_t uid)
|
|
/* Return the password file entry belonging to the user-id. */
|
|
{
|
|
struct passwd *pw;
|
|
|
|
endpwent();
|
|
while ((pw= getpwent()) != nil && pw->pw_uid != uid) {}
|
|
endpwent();
|
|
return pw;
|
|
}
|
|
|
|
struct passwd *getpwnam(const char *name)
|
|
/* Return the password file entry belonging to the user name. */
|
|
{
|
|
struct passwd *pw;
|
|
|
|
endpwent();
|
|
while ((pw= getpwent()) != nil && strcmp(pw->pw_name, name) != 0) {}
|
|
endpwent();
|
|
return pw;
|
|
}
|