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#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
#include <AK/AKString.h>
extern "C" {
#define PWDB_STR_MAX_LEN 256
struct passwd_with_strings : public passwd {
char name_buffer[PWDB_STR_MAX_LEN];
char passwd_buffer[PWDB_STR_MAX_LEN];
char gecos_buffer[PWDB_STR_MAX_LEN];
char dir_buffer[PWDB_STR_MAX_LEN];
char shell_buffer[PWDB_STR_MAX_LEN];
};
static FILE* __pwdb_stream = nullptr;
static unsigned __pwdb_line_number = 0;
static struct passwd_with_strings* __pwdb_entry = nullptr;
void setpwent()
{
__pwdb_line_number = 0;
if (__pwdb_stream) {
rewind(__pwdb_stream);
} else {
__pwdb_stream = fopen("/etc/passwd", "r");
if (!__pwdb_stream) {
perror("open /etc/passwd");
}
assert(__pwdb_stream);
__pwdb_entry = (struct passwd_with_strings*)mmap(nullptr, getpagesize(), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
set_mmap_name(__pwdb_entry, getpagesize(), "setpwent");
}
}
void endpwent()
{
__pwdb_line_number = 0;
if (__pwdb_stream) {
fclose(__pwdb_stream);
__pwdb_stream = nullptr;
}
if (__pwdb_entry) {
munmap(__pwdb_entry, getpagesize());
__pwdb_entry = nullptr;
}
}
struct passwd* getpwuid(uid_t uid)
{
setpwent();
while (auto* pw = getpwent()) {
if (pw->pw_uid == uid)
return pw;
}
return nullptr;
}
struct passwd* getpwnam(const char* name)
{
setpwent();
while (auto* pw = getpwent()) {
if (!strcmp(pw->pw_name, name))
return pw;
}
return nullptr;
}
struct passwd* getpwent()
{
if (!__pwdb_stream)
setpwent();
assert(__pwdb_stream);
if (feof(__pwdb_stream))
return nullptr;
next_entry:
char buffer[1024];
++__pwdb_line_number;
char* s = fgets(buffer, sizeof(buffer), __pwdb_stream);
if (!s)
return nullptr;
assert(__pwdb_stream);
if (feof(__pwdb_stream))
return nullptr;
String line(s, Chomp);
auto parts = line.split(':');
if (parts.size() != 7) {
fprintf(stderr, "getpwent(): Malformed entry on line %u\n", __pwdb_line_number);
goto next_entry;
}
auto& e_name = parts[0];
auto& e_passwd = parts[1];
auto& e_uid_string = parts[2];
auto& e_gid_string = parts[3];
auto& e_gecos = parts[4];
auto& e_dir = parts[5];
auto& e_shell = parts[6];
bool ok;
uid_t e_uid = e_uid_string.to_uint(ok);
if (!ok) {
fprintf(stderr, "getpwent(): Malformed UID on line %u\n", __pwdb_line_number);
goto next_entry;
}
gid_t e_gid = e_gid_string.to_uint(ok);
if (!ok) {
fprintf(stderr, "getpwent(): Malformed GID on line %u\n", __pwdb_line_number);
goto next_entry;
}
__pwdb_entry->pw_uid = e_uid;
__pwdb_entry->pw_gid = e_gid;
__pwdb_entry->pw_name = __pwdb_entry->name_buffer;
__pwdb_entry->pw_passwd = __pwdb_entry->passwd_buffer;
__pwdb_entry->pw_gecos = __pwdb_entry->gecos_buffer;
__pwdb_entry->pw_dir = __pwdb_entry->dir_buffer;
__pwdb_entry->pw_shell = __pwdb_entry->shell_buffer;
strncpy(__pwdb_entry->name_buffer, e_name.characters(), PWDB_STR_MAX_LEN);
strncpy(__pwdb_entry->passwd_buffer, e_passwd.characters(), PWDB_STR_MAX_LEN);
strncpy(__pwdb_entry->gecos_buffer, e_gecos.characters(), PWDB_STR_MAX_LEN);
strncpy(__pwdb_entry->dir_buffer, e_dir.characters(), PWDB_STR_MAX_LEN);
strncpy(__pwdb_entry->shell_buffer, e_shell.characters(), PWDB_STR_MAX_LEN);
return __pwdb_entry;
}
}
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