LibC: implement endpwent(), getpwent() and setpwent()

This commit is contained in:
Bananymous 2023-07-13 11:22:09 +03:00
parent 72041a52e8
commit 985df3532b
2 changed files with 114 additions and 0 deletions

View File

@ -8,6 +8,7 @@ set(LIBC_SOURCES
dirent.cpp dirent.cpp
fcntl.cpp fcntl.cpp
printf_impl.cpp printf_impl.cpp
pwd.cpp
stdio.cpp stdio.cpp
stdlib.cpp stdlib.cpp
string.cpp string.cpp

113
libc/pwd.cpp Normal file
View File

@ -0,0 +1,113 @@
#include <BAN/String.h>
#include <BAN/StringView.h>
#include <BAN/Vector.h>
#include <ctype.h>
#include <errno.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static FILE* s_pwent_fp = nullptr;
static passwd s_pwent_struct;
#define TRY_LIBC(expr, ret) ({ auto&& e = expr; if (e.is_error()) { errno = e.error().get_error_code(); return ret; } e.release_value(); })
static bool open_pwent()
{
if (s_pwent_fp)
return true;
s_pwent_fp = fopen("/etc/passwd", "r");
return s_pwent_fp;
}
static void clear_pwent(passwd& passwd)
{
if (passwd.pw_name)
free(passwd.pw_name);
passwd.pw_name = nullptr;
if (passwd.pw_dir)
free(passwd.pw_dir);
passwd.pw_dir = nullptr;
if (passwd.pw_shell)
free(passwd.pw_shell);
passwd.pw_shell = nullptr;
}
void endpwent(void)
{
if (!s_pwent_fp)
return;
fclose(s_pwent_fp);
s_pwent_fp = nullptr;
clear_pwent(s_pwent_struct);
}
struct passwd* getpwent(void)
{
if (!s_pwent_fp)
if (!open_pwent())
return nullptr;
clear_pwent(s_pwent_struct);
BAN::String line;
while (true)
{
char buffer[128];
if (!fgets(buffer, sizeof(buffer), s_pwent_fp))
return nullptr;
TRY_LIBC(line.append(buffer), nullptr);
if (line.back() == '\n')
{
line.pop_back();
break;
}
}
auto parts = TRY_LIBC(line.sv().split(':', true), nullptr);
ASSERT(parts.size() == 7);
ASSERT(1 <= parts[2].size() && parts[2].size() <= 9);
for (char c : parts[2])
ASSERT(isdigit(c));
ASSERT(1 <= parts[3].size() && parts[3].size() <= 9);
for (char c : parts[3])
ASSERT(isdigit(c));
s_pwent_struct.pw_uid = atoi(parts[2].data());
s_pwent_struct.pw_gid = atoi(parts[3].data());
s_pwent_struct.pw_name = (char*)malloc(parts[0].size() + 1);
if (!s_pwent_struct.pw_name)
return nullptr;
memcpy(s_pwent_struct.pw_name, parts[0].data(), parts[0].size());
s_pwent_struct.pw_name[parts[0].size()] = '\0';
s_pwent_struct.pw_dir = (char*)malloc(parts[5].size() + 1);
if (!s_pwent_struct.pw_dir)
return nullptr;
memcpy(s_pwent_struct.pw_dir, parts[5].data(), parts[5].size());
s_pwent_struct.pw_dir[parts[5].size()] = '\0';
s_pwent_struct.pw_shell = (char*)malloc(parts[6].size() + 1);
if (!s_pwent_struct.pw_shell)
return nullptr;
memcpy(s_pwent_struct.pw_shell, parts[6].data(), parts[6].size());
s_pwent_struct.pw_shell[parts[6].size()] = '\0';
return &s_pwent_struct;
}
struct passwd* getpwnam(const char* name);
int getpwnam_r(const char* name, struct passwd* pwd, char* buffer, size_t bufsize, struct passwd** result);
struct passwd* getpwuid(uid_t uid);
int getpwuid_r(uid_t uid, struct passwd* pwd, char* buffer, size_t bufsize, struct passwd** result);
void setpwent(void)
{
if (!s_pwent_fp)
return;
fseek(s_pwent_fp, 0, SEEK_SET);
}