added trap builtin

4 files changed, 165 insertions, 4 deletions

diff --git a/README.md b/README.md
index b8ac3d7..0394983 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@
 
 # Lunar Shell
 
-Lunar Shell (lush) is an open source unix shell with a single goal in mind. That goal is to offer the ability to write shell scripts for your operating system entirely in Lua. The Lua scripting language has many powerful features that allow for more control in the hands of the user to automate tasks on their machine.
+Lunar Shell (lush) is an open source Linux shell with a single goal in mind. That goal is to offer the ability to write shell scripts for your operating system entirely in Lua. The Lua scripting language has many powerful features that allow for more control in the hands of the user to automate tasks on their machine.
 
 > [!NOTE]  
 > Lunar Shell is very early in development and may be lacking in many features common of other Linux shells.
diff --git a/src/builtins.c b/src/builtins.c
index 48bfa1c..8c7739a 100644
--- a/src/builtins.c
+++ b/src/builtins.c
@@ -36,11 +36,60 @@ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 #include <time.h>
 #include <unistd.h>
 
-char *builtin_strs[] = {"cd", "help", "exit", "time"};
-char *builtin_usage[] = {"[dirname]", "", "", "[pipeline]"};
+#define MAX_SIGNALS 64
+
+lua_State *trap_L;
+
+char *traps[MAX_SIGNALS];
+
+const char *sig_strs[] = {
+	"SIGHUP",	   "SIGINT",	  "SIGQUIT",	 "SIGILL",		"SIGTRAP",
+	"SIGABRT",	   "SIGBUS",	  "SIGFPE",		 "SIGKILL",		"SIGUSR1",
+	"SIGSEGV",	   "SIGUSR2",	  "SIGPIPE",	 "SIGALRM",		"SIGTERM",
+	"SIGSTKFLT",   "SIGCHLD",	  "SIGCONT",	 "SIGSTOP",		"SIGTSTP",
+	"SIGTTIN",	   "SIGTTOU",	  "SIGURG",		 "SIGXCPU",		"SIGXFSZ",
+	"SIGVTALRM",   "SIGPROF",	  "SIGWINCH",	 "SIGIO",		"SIGPWR",
+	"SIGSYS",	   NULL,		  NULL,			 "SIGRTMIN",	"SIGRTMIN+1",
+	"SIGRTMIN+2",  "SIGRTMIN+3",  "SIGRTMIN+4",	 "SIGRTMIN+5",	"SIGRTMIN+6",
+	"SIGRTMIN+7",  "SIGRTMIN+8",  "SIGRTMIN+9",	 "SIGRTMIN+10", "SIGRTMIN+11",
+	"SIGRTMIN+12", "SIGRTMIN+13", "SIGRTMIN+14", "SIGRTMIN+15", "SIGRTMAX-14",
+	"SIGRTMAX-13", "SIGRTMAX-12", "SIGRTMAX-11", "SIGRTMAX-10", "SIGRTMAX-9",
+	"SIGRTMAX-8",  "SIGRTMAX-7",  "SIGRTMAX-6",	 "SIGRTMAX-5",	"SIGRTMAX-4",
+	"SIGRTMAX-3",  "SIGRTMAX-2",  "SIGRTMAX-1",	 "SIGRTMAX"};
+
+static int trap_exec(const char *line) {
+	int status = 0;
+	lush_push_history(line);
+	char *expanded_line = lush_resolve_aliases((char *)line);
+	char **commands = lush_split_commands(expanded_line);
+	char ***args = lush_split_args(commands, &status);
+
+	if (status == -1) {
+		fprintf(stderr, "lush: Expected end of quoted string\n");
+	} else if (lush_run(trap_L, args, status) != 0) {
+		return -1;
+	}
+
+	for (int i = 0; args[i]; i++) {
+		free(args[i]);
+	}
+	free(args);
+	free(commands);
+	return 0;
+}
+
+void trap_handler(int signum) {
+	if (traps[signum - 1]) {
+		trap_exec(traps[signum - 1]);
+	}
+}
+
+char *builtin_strs[] = {"cd", "help", "exit", "time", "trap"};
+char *builtin_usage[] = {"[dirname]", "", "", "[pipeline]",
+						 "[-lp] [[command] signal]"};
 
 int (*builtin_func[])(lua_State *, char ***) = {
-	&lush_cd, &lush_help, &lush_exit, &lush_time, &lush_lua};
+	&lush_cd, &lush_help, &lush_exit, &lush_time, &lush_trap, &lush_lua};
 
 int lush_num_builtins() { return sizeof(builtin_strs) / sizeof(char *); }
 
@@ -176,6 +225,92 @@ int lush_time(lua_State *L, char ***args) {
 	return rc;
 }
 
+int lush_trap(lua_State *L, char ***args) {
+	args[0]++;
+	// check for -lp
+	if (args[0][0][0] == '-') {
+		if (strchr(args[0][0], 'l')) {
+			// list all the signals
+			printf("1) SIGHUP	 2) SIGINT	 3) "
+				   "SIGQUIT	 4) SIGILL	 5) SIGTRAP\n"
+				   "6) SIGABRT	 7) SIGBUS	 8) "
+				   "SIGFPE	 9) SIGKILL	10) SIGUSR1\n"
+				   "11) SIGSEGV	12) SIGUSR2	13) "
+				   "SIGPIPE	14) SIGALRM	15) "
+				   "SIGTERM\n"
+				   "16) SIGSTKFLT	17) SIGCHLD	18) "
+				   "SIGCONT	19) SIGSTOP	20) "
+				   "SIGTSTP\n"
+				   "21) SIGTTIN	22) SIGTTOU	23) "
+				   "SIGURG	24) SIGXCPU	25) "
+				   "SIGXFSZ\n"
+				   "26) SIGVTALRM	27) SIGPROF	28) "
+				   "SIGWINCH	29) SIGIO	30) "
+				   "SIGPWR\n"
+				   "31) SIGSYS	34) SIGRTMIN	35) "
+				   "SIGRTMIN+1	36) SIGRTMIN+2	"
+				   "37) SIGRTMIN+3\n"
+				   "38) SIGRTMIN+4	39) SIGRTMIN+5	40) "
+				   "SIGRTMIN+6	41) "
+				   "SIGRTMIN+7	42) SIGRTMIN+8\n"
+				   "43) SIGRTMIN+9	44) SIGRTMIN+10	45) "
+				   "SIGRTMIN+11	46) "
+				   "SIGRTMIN+12	47) SIGRTMIN+13\n"
+				   "48) SIGRTMIN+14	49) SIGRTMIN+15	50) "
+				   "SIGRTMAX-14	51) "
+				   "SIGRTMAX-13	52) SIGRTMAX-12\n"
+				   "53) SIGRTMAX-11	54) SIGRTMAX-10	55) "
+				   "SIGRTMAX-9	56) "
+				   "SIGRTMAX-8	57) SIGRTMAX-7\n"
+				   "58) SIGRTMAX-6	59) SIGRTMAX-5	60) "
+				   "SIGRTMAX-4	61) "
+				   "SIGRTMAX-3	62) SIGRTMAX-2\n"
+				   "63) SIGRTMAX-1	64) SIGRTMAX\n");
+			args[0]--;
+			return 0;
+		}
+		if (strchr(args[0][0], 'p')) {
+			for (int i = 0; i < MAX_SIGNALS; i++) {
+				if (traps[i] != NULL) {
+					printf("trap -- '%s' %s\n", traps[i], sig_strs[i]);
+				}
+			}
+			args[0]--;
+			return 0;
+		}
+		if (strlen(args[0][0]) == 1) {
+			// check for unbinding
+			for (int i = 0; i < MAX_SIGNALS; i++) {
+				if (sig_strs[i] && strcmp(args[0][1], sig_strs[i]) == 0) {
+					if (i == 1) {
+						// SIGINT is a special case for parent process
+						signal(i + 1, SIG_IGN);
+					} else {
+						signal(i + 1, SIG_DFL);
+					}
+					break;
+				}
+			}
+			args[0]--;
+			return 0;
+		}
+	}
+
+	if (args[0][0] && args[0][1]) {
+		for (int i = 0; i < MAX_SIGNALS; i++) {
+			if (sig_strs[i] && strcmp(args[0][1], sig_strs[i]) == 0) {
+				traps[i] = strdup(args[0][0]);
+				trap_L = L; // idk if I like this but doing it for now
+				signal(i + 1, trap_handler);
+				break;
+			}
+		}
+	}
+
+	args[0]--;
+	return 0;
+}
+
 int lush_lua(lua_State *L, char ***args) {
 	// run the lua file given
 	const char *script = args[0][0];
diff --git a/src/lush.h b/src/lush.h
index d6022b4..06eb184 100644
--- a/src/lush.h
+++ b/src/lush.h
@@ -35,6 +35,7 @@ int lush_cd(lua_State *L, char ***args);
 int lush_help(lua_State *L, char ***args);
 int lush_exit(lua_State *L, char ***args);
 int lush_time(lua_State *L, char ***args);
+int lush_trap(lua_State *L, char ***args);
 int lush_lua(lua_State *L, char ***args);
 
 int lush_num_builtins();
diff --git a/update.sh b/update.sh
new file mode 100644
index 0000000..58e1e2f
--- /dev/null
+++ b/update.sh
@@ -0,0 +1,25 @@
+#!/bin/sh
+
+premake5 gmake
+make
+if [ ! -d ~/.lush ]; then
+    cp -rf ./.lush ~/
+fi
+
+# always update example
+cp -f ./.lush/scripts/example.lua ~/.lush/scripts/example.lua
+
+# Install the new shell binary to a temporary location
+sudo cp ./bin/Debug/lush/lush /usr/bin/lush.new
+
+# Atomically replace the old binary
+sudo mv /usr/bin/lush.new /usr/bin/lush
+
+# Ensure the shell is registered in /etc/shells
+if ! grep -Fxq "/usr/bin/lush" /etc/shells; then
+    echo "/usr/bin/lush" | sudo tee -a /etc/shells >/dev/null
+fi
+
+echo "====================="
+echo "   UPDATE FINISHED   "
+echo "====================="