added support for init.lua for configuring shell

8 files changed, 180 insertions, 38 deletions

diff --git a/.lush/init.lua b/.lush/init.lua
new file mode 100644
index 0000000..26fe71e
--- /dev/null
+++ b/.lush/init.lua
@@ -0,0 +1,35 @@
+--[[
+Copyright (c) 2024, Lance Borden
+All rights reserved.
+
+This software is licensed under the BSD 3-Clause License.
+You may obtain a copy of the license at:
+https://opensource.org/licenses/BSD-3-Clause
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted under the conditions stated in the BSD 3-Clause
+License.
+
+THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTIES,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+]]
+
+-- This file is your init.lua. It will be automatically executed each time you open
+-- a new session of Lunar Shell.
+
+-- Setting environment variables
+local path = lush.getenv("HOME") .. "/bin:" .. lush.getenv("PATH")
+lush.setenv("PATH", path)
+
+-- the prompt can be customized here too
+-- %u is username, %h is hostname, %w is current working directory
+lush.setPrompt("[%u@%h: %w]")
+-- any global functions that accept either no parameters or just an array of args
+-- will be read in and stored as built in commands for the shell
+function my_command(args)
+	print("my custom command")
+end
+
+-- all functions from the Lunar Shell Lua API are available to you to
+-- customize your startup however you want
diff --git a/.lush/scripts/example.lua b/.lush/scripts/example.lua
index 4d0b8fa..c60f99b 100644
--- a/.lush/scripts/example.lua
+++ b/.lush/scripts/example.lua
@@ -84,7 +84,10 @@ print("Most recent history: " .. lush.lastHistory())
 print("Most recent history indexed: " .. lush.getHistory(1))
 
 -- you can set environment variables using putenv
-lush.putenv("EXAMPLE=Lunar Shell Example")
+lush.setenv("EXAMPLE", "Lunar Shell Example")
 
 -- you can get an environment variable using getenv
 print("Value of EXAMPLE: " .. lush.getenv("EXAMPLE"))
+
+-- you can unset an environment variable with unsetenv
+lush.unsetenv("EXAMPLE")
diff --git a/install.sh b/install.sh
index bdcfe2e..ebdbaeb 100644
--- a/install.sh
+++ b/install.sh
@@ -51,7 +51,12 @@ rm premake.tar.gz
 
 premake5 gmake
 make
-cp -rf ./.lush ~/
+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
diff --git a/src/lua_api.c b/src/lua_api.c
index e28d7c1..2f967e6 100644
--- a/src/lua_api.c
+++ b/src/lua_api.c
@@ -29,7 +29,7 @@ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 #include <sys/stat.h>
 #include <unistd.h>
 
-// global for checking if debug_mode is toggled
+// globals
 static bool debug_mode = false;
 
 // -- script execution --
@@ -56,7 +56,7 @@ void lua_load_script(lua_State *L, const char *script, char **args) {
 		}
 	}
 	// add args global if args were passed
-	if (args[0] != NULL) {
+	if (args != NULL && args[0] != NULL) {
 		lua_newtable(L);
 		for (int i = 0; args[i]; i++) {
 			lua_pushstring(L, args[i]);
@@ -79,6 +79,12 @@ void lua_load_script(lua_State *L, const char *script, char **args) {
 	}
 }
 
+void lua_run_init(lua_State *L) {
+	char script_path[64];
+	snprintf(script_path, sizeof(script_path), ".lush/%s", "init.lua");
+	lua_load_script(L, script_path, NULL);
+}
+
 // -- C funtions --
 static int execute_command(lua_State *L, const char *line) {
 	int status = 0;
@@ -284,9 +290,38 @@ static int l_get_env(lua_State *L) {
 	return 1;
 }
 
-static int l_put_env(lua_State *L) {
+static int l_set_env(lua_State *L) {
+	const char *env_name = luaL_checkstring(L, 1);
+	const char *env_value = luaL_checkstring(L, 2);
+	setenv(env_name, env_value, 1);
+	return 0;
+}
+
+static int l_unset_env(lua_State *L) {
 	const char *env = luaL_checkstring(L, 1);
-	putenv((char *)env);
+	unsetenv(env);
+	return 0;
+}
+
+static int l_set_prompt(lua_State *L) {
+	const char *format = luaL_checkstring(L, 1);
+	if (format == NULL) {
+		perror("string format not passed");
+		return 0;
+	}
+
+	// free old prompt format if necessary
+	if (prompt_format) {
+		free(prompt_format);
+	}
+
+	prompt_format = malloc(strlen(format) + 1);
+
+	if (prompt_format) {
+		strcpy(prompt_format, format);
+	} else {
+		perror("malloc failed");
+	}
 	return 0;
 }
 
@@ -320,8 +355,12 @@ void lua_register_api(lua_State *L) {
 	lua_setfield(L, -2, "getHistory");
 	lua_pushcfunction(L, l_get_env);
 	lua_setfield(L, -2, "getenv");
-	lua_pushcfunction(L, l_put_env);
-	lua_setfield(L, -2, "putenv");
+	lua_pushcfunction(L, l_set_env);
+	lua_setfield(L, -2, "setenv");
+	lua_pushcfunction(L, l_unset_env);
+	lua_setfield(L, -2, "unsetenv");
+	lua_pushcfunction(L, l_set_prompt);
+	lua_setfield(L, -2, "setPrompt");
 	// set the table as global
 	lua_setglobal(L, "lush");
 }
diff --git a/src/lua_api.h b/src/lua_api.h
index c9f61ab..9027040 100644
--- a/src/lua_api.h
+++ b/src/lua_api.h
@@ -21,6 +21,7 @@ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 #include <lua.h>
 
 void lua_load_script(lua_State *L, const char *script, char **args);
+void lua_run_init(lua_State *L);
 void lua_register_api(lua_State *L);
 
 #endif
diff --git a/src/lush.c b/src/lush.c
index a3fbb93..8e5bb6f 100644
--- a/src/lush.c
+++ b/src/lush.c
@@ -40,6 +40,9 @@ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 
 #define BUFFER_SIZE 1024
 
+// initialize prompt format
+char *prompt_format = NULL;
+
 // -- builtin functions --
 char *builtin_strs[] = {"cd", "help", "exit", "time"};
 
@@ -163,10 +166,67 @@ static int get_terminal_width() {
 	return w.ws_col;
 }
 
+static size_t get_prompt_len(const char *format, const char *username,
+							 const char *hostname, const char *cwd) {
+	size_t prompt_len = 0;
+
+	while (*format) {
+		if (strncmp(format, "%u", 2) == 0) {
+			prompt_len += strlen(username);
+			format += 2;
+		} else if (strncmp(format, "%h", 2) == 0) {
+			prompt_len += strlen(hostname);
+			format += 2;
+		} else if (strncmp(format, "%w", 2) == 0) {
+			prompt_len += strlen(cwd);
+			format += 2;
+		} else {
+			prompt_len++;
+			format++;
+		}
+	}
+	return prompt_len;
+}
+
+static char *format_prompt_string(const char *input, const char *username,
+								  const char *hostname, const char *cwd) {
+	// Calculate the size of the new string
+	size_t new_size = get_prompt_len(input, username, hostname, cwd) + 1;
+
+	// Allocate memory for the new string
+	char *result = (char *)malloc(new_size);
+	if (!result) {
+		return NULL; // Handle memory allocation failure
+	}
+
+	// Replace placeholders in the input string and build the result string
+	char *dest = result;
+	while (*input) {
+		if (strncmp(input, "%u", 2) == 0) {
+			strcpy(dest, username);
+			dest += strlen(username);
+			input += 2;
+		} else if (strncmp(input, "%h", 2) == 0) {
+			strcpy(dest, hostname);
+			dest += strlen(hostname);
+			input += 2;
+		} else if (strncmp(input, "%w", 2) == 0) {
+			strcpy(dest, cwd);
+			dest += strlen(cwd);
+			input += 2;
+		} else {
+			*dest++ = *input++;
+		}
+	}
+
+	*dest = '\0'; // Null-terminate the result string
+	return result;
+}
+
 static char *get_prompt() {
 	char *username = getenv("USER");
-	char device_name[256];
-	gethostname(device_name, sizeof(device_name));
+	char hostname[256];
+	gethostname(hostname, sizeof(hostname));
 	char *cwd = getcwd(NULL, 0);
 
 	// Replace /home/<user> with ~
@@ -182,12 +242,20 @@ static char *get_prompt() {
 		prompt_cwd = strdup(cwd);
 	}
 
-	// Print the prompt
-	size_t prompt_len =
-		strlen(prompt_cwd) + strlen(username) + strlen(device_name) + 6;
-	char *prompt = (char *)malloc(prompt_len);
-	snprintf(prompt, prompt_len, "[%s@%s:%s]", username, device_name,
-			 prompt_cwd);
+	// get the prompt if no format in init.lua
+	if (prompt_format == NULL) {
+		size_t prompt_len =
+			strlen(prompt_cwd) + strlen(username) + strlen(hostname) + 6;
+		char *prompt = (char *)malloc(prompt_len);
+		snprintf(prompt, prompt_len, "[%s@%s:%s]", username, hostname,
+				 prompt_cwd);
+		free(cwd);
+		return prompt;
+	}
+
+	// get formatted prompt
+	char *prompt =
+		format_prompt_string(prompt_format, username, hostname, prompt_cwd);
 
 	free(cwd);
 	return prompt;
@@ -581,9 +649,11 @@ int main(int argc, char *argv[]) {
 #endif
 		return 0;
 	}
+	// init lua state
 	lua_State *L = luaL_newstate();
 	luaL_openlibs(L);
 	lua_register_api(L);
+	lua_run_init(L);
 	// eat ^C in main
 	struct sigaction sa;
 	sa.sa_handler = SIG_IGN;
@@ -594,28 +664,9 @@ int main(int argc, char *argv[]) {
 	int status = 0;
 	while (true) {
 		// Prompt
-		char *username = getenv("USER");
-		char device_name[256];
-		gethostname(device_name, sizeof(device_name));
-		char *cwd = getcwd(NULL, 0);
-
-		// Replace /home/<user> with ~
-		char *home_prefix = "/home/";
-		size_t home_len = strlen(home_prefix) + strlen(username);
-		char *prompt_cwd;
-		if (strncmp(cwd, home_prefix, strlen(home_prefix)) == 0 &&
-			strncmp(cwd + strlen(home_prefix), username, strlen(username)) ==
-				0) {
-			prompt_cwd = malloc(strlen(cwd) - home_len +
-								2); // 1 for ~ and 1 for null terminator
-			snprintf(prompt_cwd, strlen(cwd) - home_len + 2, "~%s",
-					 cwd + home_len);
-		} else {
-			prompt_cwd = strdup(cwd);
-		}
+		char *prompt = get_prompt();
 
-		// Print the prompt
-		printf("[%s@%s:%s] ", username, device_name, prompt_cwd);
+		printf("%s ", prompt);
 		char *line = lush_read_line();
 		lush_push_history(line);
 		printf("\n");
@@ -635,11 +686,14 @@ int main(int argc, char *argv[]) {
 			free(args[i]);
 		}
 		// add last line to history
-		free(cwd);
+		free(prompt);
 		free(args);
 		free(commands);
 		free(line);
 	}
 	lua_close(L);
+	if (prompt_format != NULL)
+		free(prompt_format);
+
 	return 0;
 }
diff --git a/src/lush.h b/src/lush.h
index bc8dc3c..ea575c7 100644
--- a/src/lush.h
+++ b/src/lush.h
@@ -37,4 +37,9 @@ char ***lush_split_args(char **commands, int *status);
 void lush_execute_command(char **args, int input_fd, int output_fd);
 int lush_execute_pipeline(char ***commands, int num_commands);
 
+void lush_format_prompt(const char *prompt_format);
+
+// format spec for the prompt
+extern char *prompt_format;
+
 #endif // LUSH_H
diff --git a/vgcore.250513 b/vgcore.250513
new file mode 100644
index 0000000..85ad236
--- /dev/null
+++ b/vgcore.250513