Add getpwent() family of functions to LibC.

Also add a little /etc/passwd database. There's just me in there.

AK/Compiler.h

@@ -2,6 +2,7 @@
 
 #define PACKED __attribute__ ((packed))
 #define NORETURN __attribute__ ((noreturn))
+#undef ALWAYS_INLINE
 #define ALWAYS_INLINE __attribute__ ((always_inline))
 #define NEVER_INLINE __attribute__ ((noinline))
 #define MALLOC_ATTR __attribute__ ((malloc))

AK/String.cpp

@@ -75,4 +75,19 @@ ByteBuffer String::toByteBuffer() const
     return ByteBuffer::copy(reinterpret_cast<const byte*>(characters()), length());
 }
 
+unsigned String::toUInt(bool& ok) const
+{
+    unsigned value = 0;
+    for (size_t i = 0; i < length(); ++i) {
+        if (characters()[i] < '0' || characters()[i] > '9') {
+            ok = false;
+            return 0;
+        }
+        value = value * 10;
+        value += characters()[i] - '0';
+    }
+    ok = true;
+    return value;
+}
+
 }

AK/String.h

@@ -44,6 +44,8 @@ public:
     {
     }
 
+    unsigned toUInt(bool& ok) const;
+
     String toLowercase() const
     {
         if (!m_impl)

Base/etc/passwd

@@ -0,0 +1,2 @@
+root:x:0:0:root:/:/bin/sh
+andreas:x:100:100:Andreas Kling,,,:/users/andreas:/bin/sh

Kernel/sync-sh

@@ -1,6 +1,7 @@
 cp -p _fs_contents.stock _fs_contents
 mkdir mnt
 mount -o loop _fs_contents mnt/
+cp -R ../Base/* mnt/
 cp ../Userland/sh mnt/bin/sh
 cp ../Userland/id mnt/bin/id
 cp ../Userland/ps mnt/bin/ps

LibC/Makefile

@@ -19,6 +19,7 @@ LIBC_OBJS = \
        signal.o \
        getopt.o \
        scanf.o \
+       pwd.o \
        entry.o
 
 OBJS = $(AK_OBJS) $(LIBC_OBJS)

LibC/ctype.h

@@ -9,7 +9,7 @@ ALWAYS_INLINE int isascii(int ch)
 
 ALWAYS_INLINE int isspace(int ch)
 {
-    return ch == ' ' || ch == '\f' || ch == '\n' || ch == '\r' || ch == '\t' == '\v';
+    return ch == ' ' || ch == '\f' || ch == '\n' || ch == '\r' || ch == '\t' || ch == '\v';
 }
 
 ALWAYS_INLINE int islower(int c)

LibC/pwd.cpp

@@ -0,0 +1,117 @@
+#include <pwd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <AK/String.h>
+
+struct passwd_with_strings : public passwd {
+    char name_buffer[256];
+    char passwd_buffer[256];
+    char gecos_buffer[256];
+    char dir_buffer[256];
+    char shell_buffer[256];
+};
+
+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");
+        __pwdb_entry = (struct passwd_with_strings*)mmap(nullptr, getpagesize());
+    }
+}
+
+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();
+
+    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;
+    if (feof(__pwdb_stream))
+        return nullptr;
+    String line(s);
+    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.toUInt(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.toUInt(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(), e_name.length());
+    strncpy(__pwdb_entry->passwd_buffer, e_passwd.characters(), e_passwd.length());
+    strncpy(__pwdb_entry->gecos_buffer, e_gecos.characters(), e_gecos.length());
+    strncpy(__pwdb_entry->dir_buffer, e_dir.characters(), e_dir.length());
+    strncpy(__pwdb_entry->shell_buffer, e_shell.characters(), e_shell.length());
+    return __pwdb_entry;
+}

LibC/pwd.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+__BEGIN_DECLS
+
+struct passwd {
+    char* pw_name;
+    char* pw_passwd;
+    uid_t pw_uid;
+    gid_t pw_gid;
+    char* pw_gecos;
+    char* pw_dir;
+    char* pw_shell;
+};
+
+struct passwd* getpwent();
+void setpwent();
+void endpwent();
+struct passwd* getpwnam(const char* name);
+struct passwd* getpwuid(uid_t);
+
+__END_DECLS

LibC/stdio.cpp

@@ -42,7 +42,7 @@ char* fgets(char* buffer, int size, FILE* stream)
 int fgetc(FILE* stream)
 {
     char ch;
-    read(stream->fd, &ch, 1);
+    fread(&ch, sizeof(char), 1, stream);
     return ch;
 }
 

LibC/stdio.h

@@ -31,6 +31,9 @@ int getc(FILE*);
 int getchar();
 FILE* fopen(const char* pathname, const char* mode);
 int fclose(FILE*);
+void rewind(FILE*);
+void clearerr(FILE*);
+int feof(FILE*);
 size_t fread(void* ptr, size_t size, size_t nmemb, FILE*);
 size_t fwrite(const void* ptr, size_t size, size_t nmemb, FILE*);
 int fprintf(FILE*, const char* fmt, ...);

LibC/sys/cdefs.h

@@ -9,4 +9,3 @@
 #define __BEGIN_DECLS
 #define __END_DECLS
 #endif
-

LibC/sys/mman.h

@@ -0,0 +1 @@
+#include <mman.h>

LibC/unistd.h

@@ -7,6 +7,7 @@ __BEGIN_DECLS
 
 extern char** environ;
 
+inline int getpagesize() { return 4096; }
 uid_t getuid();
 gid_t getgid();
 pid_t getpid();

Userland/Makefile

@@ -3,7 +3,6 @@ OBJS = \
        sh.o \
        ps.o \
        ls.o \
-       pwd.o \
        sleep.o \
        date.o \
        true.o \
@@ -21,7 +20,6 @@ APPS = \
        sh \
        ps \
        ls \
-       pwd \
        sleep \
        date \
        true \
@@ -64,9 +62,6 @@ ps: ps.o
 ls: ls.o
 	$(LD) -o $@ $(LDFLAGS) $< ../LibC/LibC.a
 
-pwd: pwd.o
-	$(LD) -o $@ $(LDFLAGS) $< ../LibC/LibC.a
-
 sleep: sleep.o
 	$(LD) -o $@ $(LDFLAGS) $< ../LibC/LibC.a
 

Userland/id.cpp

@@ -1,12 +1,15 @@
 #include <LibC/unistd.h>
 #include <LibC/stdio.h>
+#include <LibC/pwd.h>
 
 int main(int c, char** v)
 {
     uid_t uid = getuid();
     gid_t gid = getgid();
-    pid_t pid = getpid();
-    printf("uid=%u, gid=%u, pid=%u\n", uid, gid, pid);
+
+    struct passwd* pw = getpwuid(uid);
+
+    printf("uid=%u(%s), gid=%u\n", uid, pw ? pw->pw_name : "n/a", gid);
     return 0;
 }
 

Userland/pwd.cpp

@@ -1,15 +0,0 @@
-#include <LibC/unistd.h>
-#include <LibC/stdio.h>
-
-int main(int c, char** v)
-{
-    char buffer[1024];
-    char* ptr = getcwd(buffer, sizeof(buffer));
-    if (!ptr) {
-        printf("getcwd() failed\n");
-        return 1;
-    }
-    printf("%s\n", ptr);
-    return 0;
-}
-