From 237184a8bf52b2a4656f2031210b12d2b5d24ba5 Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Mon, 10 Jul 2023 21:39:22 +0200
Subject: [PATCH] libc+sh: Implement strsignal and use it in the shell

---
 apps/sh.cpp           | 10 +++++++++-
 libc/include/string.h |  3 +++
 libc/src/string.cpp   | 29 +++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/apps/sh.cpp b/apps/sh.cpp
index 7f247eb9..6bca57cf 100644
--- a/apps/sh.cpp
+++ b/apps/sh.cpp
@@ -6,6 +6,7 @@
 #include <os/FileSystem.h>
 #include <os/Process.h>
 #include <pwd.h>
+#include <signal.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -117,7 +118,14 @@ Result<int> luna_main(int argc, char** argv)
 
         if (child == 0) { TRY(execute_command(cmd.view())); }
 
-        TRY(os::Process::wait(child, nullptr));
+        int status;
+        TRY(os::Process::wait(child, &status));
+
+        if (WIFSIGNALED(status))
+        {
+            int sig = WTERMSIG(status);
+            if (sig != SIGINT && sig != SIGQUIT) os::println("[sh] Process %d exited: %s", child, strsignal(sig));
+        }
     }
 
     return 0;
diff --git a/libc/include/string.h b/libc/include/string.h
index 3349a828..aff7a35b 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -62,6 +62,9 @@ extern "C"
     /* Return the human-readable description of an error number. */
     char* strerror(int errnum);
 
+    /* Return the human-readable description of a signal number. */
+    char* strsignal(int signo);
+
     /* Return the length of the initial segment of str which consists only of bytes in accept. */
     size_t strspn(const char* str, const char* accept);
 
diff --git a/libc/src/string.cpp b/libc/src/string.cpp
index eabdc00a..510c465e 100644
--- a/libc/src/string.cpp
+++ b/libc/src/string.cpp
@@ -1,3 +1,4 @@
+#include <bits/signal.h>
 #include <luna/SystemError.h>
 #include <string.h>
 
@@ -12,4 +13,32 @@ extern "C"
     {
         return const_cast<char*>(error_string(errnum));
     }
+
+    static const char* __internal_strsignal(int signo)
+    {
+        switch (signo)
+        {
+        case SIGHUP: return "Hangup";
+        case SIGINT: return "Terminal interrupt";
+        case SIGQUIT: return "Terminal quit";
+        case SIGILL: return "Invalid opcode";
+        case SIGTRAP: return "Breakpoint trap";
+        case SIGABRT: return "Aborted";
+        case SIGCHLD: return "Child stopped or exited";
+        case SIGFPE: return "Floating point exception";
+        case SIGKILL: return "Killed";
+        case SIGSTOP: return "Stopped";
+        case SIGSEGV: return "Segmentation fault";
+        case SIGCONT: return "Continued";
+        case SIGPIPE: return "Broken pipe";
+        case SIGALRM: return "Alarm signal";
+        case SIGTERM: return "Terminated";
+        default: return "Unknown signal";
+        }
+    }
+
+    char* strsignal(int signo)
+    {
+        return const_cast<char*>(__internal_strsignal(signo));
+    }
 }