Add sys$uname() and a /bin/uname utility.

Kernel/Syscall.cpp

@@ -112,6 +112,8 @@ DWORD handle(DWORD function, DWORD arg1, DWORD arg2, DWORD arg3)
         return current->sys$get_arguments((int*)arg1, (char***)arg2);
     case Syscall::PosixChdir:
         return current->sys$chdir((const char*)arg1);
+    case Syscall::PosixUname:
+        return current->sys$uname((utsname*)arg1);
     default:
         kprintf("int0x80: Unknown function %x requested {%x, %x, %x}\n", function, arg1, arg2, arg3);
         break;

Kernel/Syscall.h

@@ -33,6 +33,7 @@ enum Function {
     PosixGethostname = 0x2001,
     GetArguments = 0x2002,
     PosixChdir = 0x2003,
+    PosixUname = 0x2004,
 };
 
 void initialize();

Kernel/Task.cpp

@@ -26,12 +26,18 @@ static InlineLinkedList<Task>* s_tasks;
 static InlineLinkedList<Task>* s_deadTasks;
 static String* s_hostname;
 
-static String& hostname(InterruptDisabler&)
+static String& hostnameStorage(InterruptDisabler&)
 {
     ASSERT(s_hostname);
     return *s_hostname;
 }
 
+static String getHostname()
+{
+    InterruptDisabler disabler;
+    return hostnameStorage(disabler).isolatedCopy();
+}
+
 static bool contextSwitch(Task*);
 
 static void redoKernelTaskTSS()
@@ -177,14 +183,10 @@ int Task::sys$munmap(void* addr, size_t size)
 
 int Task::sys$gethostname(char* buffer, size_t size)
 {
-    String hn;
+    auto hostname = getHostname();
-    {
+    if (size < (hostname.length() + 1))
-        InterruptDisabler disabler;
-        hn = hostname(disabler).isolatedCopy();
-    }
-    if (size < (hn.length() + 1))
         return -ENAMETOOLONG;
-    memcpy(buffer, hn.characters(), size);
+    memcpy(buffer, hostname.characters(), size);
     return 0;
 }
 
@@ -760,6 +762,16 @@ int Task::sys$open(const char* path, size_t pathLength)
     return fd;
 }
 
+int Task::sys$uname(utsname* buf)
+{
+    strcpy(buf->sysname, "Serenity");
+    strcpy(buf->release, "1.0-dev");
+    strcpy(buf->version, "FIXME");
+    strcpy(buf->machine, "i386");
+    strcpy(buf->nodename, getHostname().characters());
+    return 0;
+}
+
 int Task::sys$kill(pid_t pid, int sig)
 {
     (void) sig;

Kernel/Task.h

@@ -104,6 +104,7 @@ public:
     int sys$gettimeofday(timeval*);
     int sys$gethostname(char* name, size_t length);
     int sys$get_arguments(int* argc, char*** argv);
+    int sys$uname(utsname*);
 
     static void initialize();
 

Kernel/sync-sh

@@ -11,5 +11,6 @@ cp ../Userland/true mnt/bin/true
 cp ../Userland/false mnt/bin/false
 cp ../Userland/hostname mnt/bin/hostname
 cp ../Userland/cat mnt/bin/cat
+cp ../Userland/uname mnt/bin/uname
 umount mnt
 sync

Kernel/types.h

@@ -31,6 +31,16 @@ struct timeval {
     suseconds_t tv_usec;
 };
 
+#define UTSNAME_ENTRY_LEN 65
+
+struct utsname {
+    char sysname[UTSNAME_ENTRY_LEN];
+    char nodename[UTSNAME_ENTRY_LEN];
+    char release[UTSNAME_ENTRY_LEN];
+    char version[UTSNAME_ENTRY_LEN];
+    char machine[UTSNAME_ENTRY_LEN];
+};
+
 struct FarPtr {
     DWORD offset { 0 };
     WORD selector { 0 };

LibC/Makefile

@@ -7,6 +7,7 @@ OBJS = \
        dirent.o \
        stdlib.o \
        time.o \
+       utsname.o \
        entry.o
 
 LIBRARY = LibC.a

LibC/stdio.cpp

@@ -1,6 +1,8 @@
 #include "stdio.h"
 #include "stdarg.h"
 #include "types.h"
+#include "string.h"
+#include "errno.h"
 #include <Kernel/Syscall.h>
 
 #define ALWAYS_INLINE __attribute__ ((always_inline))
@@ -169,5 +171,10 @@ int sprintf(char* buffer, const char* fmt, ...)
     return ret;
 }
 
+void perror(const char* s)
+{
+    printf("%s: %s\n", s, strerror(errno));
+}
+
 }
 

LibC/stdio.h

@@ -5,6 +5,7 @@ extern "C" {
 int printf(const char* fmt, ...);
 int sprintf(char* buffer, const char* fmt, ...);
 int putchar(int ch);
+void perror(const char*);
 
 }
 

LibC/utsname.cpp

@@ -0,0 +1,14 @@
+#include "utsname.h"
+#include "errno.h"
+#include <Kernel/Syscall.h>
+
+extern "C" {
+
+int uname(struct utsname* buf)
+{
+    int rc = Syscall::invoke(Syscall::PosixUname, (dword)buf);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
+
+}
+

LibC/utsname.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#define UTSNAME_ENTRY_LEN 65
+
+extern "C" {
+
+struct utsname {
+    char sysname[UTSNAME_ENTRY_LEN];
+    char nodename[UTSNAME_ENTRY_LEN];
+    char release[UTSNAME_ENTRY_LEN];
+    char version[UTSNAME_ENTRY_LEN];
+    char machine[UTSNAME_ENTRY_LEN];
+};
+
+int uname(struct utsname*);
+
+}

Userland/.gitignore

@@ -10,3 +10,4 @@ false
 true
 hostname
 cat
+uname

Userland/Makefile

@@ -9,7 +9,8 @@ OBJS = \
        true.o \
        false.o \
        hostname.o \
-       cat.o
+       cat.o \
+       uname.o
 
 APPS = \
        id \
@@ -22,7 +23,8 @@ APPS = \
        true \
        false \
        hostname \
-       cat
+       cat \
+       uname
 
 ARCH_FLAGS =
 STANDARD_FLAGS = -std=c++17 -nostdinc++ -nostdlib
@@ -75,6 +77,9 @@ hostname: hostname.o
 cat: cat.o
 	$(LD) -o $@ $(LDFLAGS) $< ../LibC/LibC.a
 
+uname: uname.o
+	$(LD) -o $@ $(LDFLAGS) $< ../LibC/LibC.a
+
 .cpp.o:
 	@echo "CXX $<"; $(CXX) $(CXXFLAGS) -o $@ -c $<
 

Userland/uname.cpp

@@ -0,0 +1,46 @@
+#include <LibC/utsname.h>
+#include <LibC/stdio.h>
+
+int main(int argc, char** argv)
+{
+    utsname uts;
+    int rc = uname(&uts);
+    if (rc < 0) {
+        perror("uname() failed");
+        return 0;
+    }
+    bool flag_s = false;
+    bool flag_n = false;
+    bool flag_r = false;
+    bool flag_m = false;
+    if (argc == 1) {
+        flag_s = true;
+    } else {
+        for (int i = 1; i < argc; ++i) {
+            if (argv[i][0] == '-') {
+                for (const char* o = &argv[i][1]; *o; ++o) {
+                    switch (*o) {
+                    case 's': flag_s = true; break;
+                    case 'n': flag_n = true; break;
+                    case 'r': flag_r = true; break;
+                    case 'm': flag_m = true; break;
+                    case 'a': flag_s = flag_n = flag_r = flag_m = true; break;
+                    }
+                }
+            }
+        }
+    }
+    if (!flag_s && !flag_n && !flag_r && !flag_m)
+        flag_s = true;
+    if (flag_s)
+        printf("%s ", uts.sysname);
+    if (flag_n)
+        printf("%s ", uts.nodename);
+    if (flag_r)
+        printf("%s ", uts.release);
+    if (flag_m)
+        printf("%s ", uts.machine);
+    printf("\n");
+    return 0;
+}
+