initial commit

9 files changed, 521 insertions, 0 deletions

diff --git a/.clang-format b/.clang-format
new file mode 100644
index 0000000..0fc6dd1
--- /dev/null
+++ b/.clang-format
@@ -0,0 +1,5 @@
+---
+UseTab: Always
+IndentWidth: 4
+TabWidth: 4
+# BasedOnStyle:  LLVM
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..6565195
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+Makefile
+*.make
+bin
+obj
+.cache
\ No newline at end of file
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..0f22be7
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,28 @@
+BSD 3-Clause License
+
+Copyright (c) 2024, Lance Borden
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its
+   contributors may be used to endorse or promote products derived from
+   this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..ed12716
--- /dev/null
+++ b/README.md
@@ -0,0 +1,26 @@
+# 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.
+
+## Compiling
+
+Clone the repo and run the install script.
+
+```
+git clone https://github.com/BanceDev/lush.git
+cd lush
+sh install.sh
+```
+
+For future compiles just run ```make``` from the root directory. If you change the premake5.lua file rebuild the makefiles with ```premake5 gmake```.
+
+## Releases
+
+Binary builds are available from [releases](https://github.com/BanceDev/lush/releases).
+
+## Contributing
+
+- For bug reports and feature suggestions please use [issues](https://github.com/BanceDev/lush/issues).
+- If you wish to contribute code of your own please submit a [pull request](https://github.com/BanceDev/lush/pulls).
+- Note: It is likely best to submit an issue before a PR to see if the feature is wanted before spending time making a commit.
+- All help is welcome!
diff --git a/compile_commands.json b/compile_commands.json
new file mode 100644
index 0000000..6578a36
--- /dev/null
+++ b/compile_commands.json
@@ -0,0 +1,16 @@
+[
+  {
+    "arguments": [
+      "/usr/bin/cc",
+      "-DDEBUG",
+      "-g",
+      "-c",
+      "-o",
+      "obj/Debug/lush.o",
+      "src/lush.c"
+    ],
+    "directory": "/home/lanceb/projects/lush",
+    "file": "/home/lanceb/projects/lush/src/lush.c",
+    "output": "/home/lanceb/projects/lush/obj/Debug/lush.o"
+  }
+]
diff --git a/install.sh b/install.sh
new file mode 100644
index 0000000..f104fa6
--- /dev/null
+++ b/install.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+
+PREMAKE_VERSION="5.0.0-beta2"
+OS="linux"
+
+echo "downloading premake $PREMAKE_VERSION"
+wget -q https://github.com/premake/premake-core/releases/download/v${PREMAKE_VERSION}/premake-${PREMAKE_VERSION}-${OS}.tar.gz -O premake.tar.gz
+echo "extracting premake"
+tar -xzf premake.tar.gz
+echo "installing premake"
+sudo mv premake5 example.so libluasocket.so /usr/bin
+sudo chmod +x /usr/bin/premake5
+rm premake.tar.gz
+
+premake5 gmake
+make
+
+sudo cp ./bin/Debug/lush/lush /usr/bin/lush
+
+if ! grep -Fxq "/usr/bin/lush" /etc/shells; then
+    echo "/usr/bin/lush" | sudo tee -a /etc/shells >/dev/null
+fi
+
+chsh -s /usr/bin/lush
+
+echo "====================="
+echo "INSTALLATION FINISHED"
+echo "====================="
diff --git a/premake5.lua b/premake5.lua
new file mode 100644
index 0000000..0fec5e5
--- /dev/null
+++ b/premake5.lua
@@ -0,0 +1,21 @@
+workspace("lush")
+configurations({ "Debug", "Release" })
+
+-- lush project
+project("lush")
+kind("ConsoleApp")
+language("C")
+targetdir("bin/%{cfg.buildcfg}/lush")
+
+files({
+	"src/**.h",
+	"src/**.c",
+})
+
+filter("configurations:Debug")
+defines({ "DEBUG" })
+symbols("On")
+
+filter("configurations:Release")
+defines({ "NDEBUG" })
+optimize("On")
diff --git a/src/lush.c b/src/lush.c
new file mode 100644
index 0000000..652a0be
--- /dev/null
+++ b/src/lush.c
@@ -0,0 +1,355 @@
+/*
+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.
+*/
+
+#include "lush.h"
+#include <bits/time.h>
+#include <linux/limits.h>
+#include <pwd.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+
+// -- builtin functions --
+char *builtin_strs[] = {"cd", "help", "exit", "time"};
+
+int (*builtin_func[])(char ***) = {&lush_cd, &lush_help, &lush_exit,
+								   &lush_time};
+
+int lush_num_builtins() { return sizeof(builtin_strs) / sizeof(char *); }
+
+int lush_cd(char ***args) {
+	uid_t uid = getuid();
+	struct passwd *pw = getpwuid(uid);
+	if (!pw) {
+		perror("retrieve home dir");
+		return 0;
+	}
+	if (args[0][1] == NULL) {
+		if (chdir(pw->pw_dir) != 0) {
+			perror("lush: cd");
+		}
+	} else {
+		char path[PATH_MAX];
+		char extended_path[PATH_MAX];
+		char *tilda = strchr(args[0][1], '~');
+		if (tilda) {
+			strcpy(path, pw->pw_dir);
+			strcat(path, tilda + 1);
+		} else {
+			strcpy(path, args[0][1]);
+		}
+		char *exp_path = realpath(path, extended_path);
+		if (!exp_path) {
+			perror("realpath");
+			return 0;
+		}
+		if (chdir(exp_path) != 0) {
+			perror("lush: cd");
+		}
+	}
+
+	return 1;
+}
+
+int lush_help(char ***args) {
+	// TODO: make this more fun
+	printf("Lunar Shell Help Page\n\n");
+	printf("Available commands: \n");
+	for (int i = 0; i < lush_num_builtins(); i++) {
+		printf("- %s\n", builtin_strs[i]);
+	}
+	return 1;
+}
+
+int lush_exit(char ***args) { return 0; }
+
+int lush_time(char ***args) {
+	// advance past time command
+	args[0]++;
+
+	// count commands
+	int i = 0;
+	while (args[i++]) {
+		;
+	}
+
+	// get time
+	struct timespec start, end;
+	double elapsed_time;
+
+	clock_gettime(CLOCK_MONOTONIC, &start);
+	int rc = lush_run(args, i);
+	clock_gettime(CLOCK_MONOTONIC, &end);
+
+	elapsed_time = (end.tv_sec - start.tv_sec) * 1000.0 +
+				   (end.tv_nsec - start.tv_nsec) / 1e6;
+	printf("Time: %.3f milliseconds", elapsed_time);
+
+	// return pointer back to "time" for free()
+	args[0]--;
+	return rc;
+}
+
+// -- shell utility --
+char *lush_read_line() {
+	char *line = NULL;
+	size_t bufsize = 0;
+	if (getline(&line, &bufsize, stdin) == -1) {
+		if (feof(stdin)) {
+			exit(EXIT_SUCCESS);
+		} else {
+			perror("readline");
+			exit(EXIT_FAILURE);
+		}
+	}
+	return line;
+}
+
+char **lush_split_pipes(char *line) {
+	char **commands = calloc(16, sizeof(char *));
+	if (!commands) {
+		perror("calloc failed");
+		exit(1);
+	}
+
+	char *command;
+	int pos = 0;
+
+	command = strtok(line, "|");
+	while (command) {
+		commands[pos++] = command;
+		command = strtok(NULL, "|");
+	}
+
+	// trim off whitespace
+	for (int i = 0; i < pos; i++) {
+		while (*commands[i] == ' ' || *commands[i] == '\n') {
+			commands[i]++;
+		}
+		char *end_of_str = strrchr(commands[i], '\0');
+		--end_of_str;
+		while (*end_of_str == ' ' || *end_of_str == '\n') {
+			*end_of_str = '\0';
+			--end_of_str;
+		}
+	}
+	return commands;
+}
+
+char ***lush_split_args(char **commands, int *status) {
+	int outer_pos = 0;
+	char ***command_args = calloc(128, sizeof(char **));
+	if (!command_args) {
+		perror("calloc failed");
+		exit(1);
+	}
+
+	for (int i = 0; commands[i]; i++) {
+		int pos = 0;
+		char **args = calloc(128, sizeof(char *));
+		if (!args) {
+			perror("calloc failed");
+			exit(1);
+		}
+
+		bool inside_string = false;
+		char *current_token = &commands[i][0];
+		for (int j = 0; commands[i][j]; j++) {
+			if (commands[i][j] == '"' && !inside_string) {
+				// beginning of a string
+				commands[i][j++] = '\0';
+				if (commands[i][j] != '"') {
+					inside_string = true;
+					current_token = &commands[i][j];
+				} else {
+					commands[i][j] = '\0';
+					current_token = &commands[i][++j];
+				}
+			} else if (inside_string) {
+				if (commands[i][j] == '"') {
+					// ending of a string
+					inside_string = false;
+					commands[i][j] = '\0';
+					args[pos++] = current_token;
+					current_token = NULL;
+				} else {
+					// character in string
+					continue;
+				}
+			} else if (commands[i][j] == ' ') {
+				// space delimeter
+				if (current_token && *current_token != ' ') {
+					args[pos++] = current_token;
+				}
+				current_token = &commands[i][j + 1]; // go past the space
+				commands[i][j] = '\0';				 // null the space
+			} else if (commands[i][j] == '$' && commands[i][j + 1] &&
+					   commands[i][j + 1] != ' ') {
+				// environment variable
+				args[pos++] = getenv(&commands[i][++j]);
+				while (commands[i][j]) {
+					++j;
+				}
+				current_token = &commands[i][j + 1];
+			} else {
+				// regular character
+				continue;
+			}
+		}
+
+		// verify that string literals are finished
+		if (inside_string) {
+			*status = -1;
+			return command_args;
+		} else if (current_token && *current_token != ' ') {
+			// tack on last arg
+			args[pos++] = current_token;
+		}
+
+		// add this commands args array to the outer array
+		command_args[outer_pos++] = args;
+	}
+
+	*status = outer_pos;
+	return command_args;
+}
+
+int lush_execute_pipeline(char ***commands, int num_commands) {
+	// no command given
+	if (commands[0][0][0] == '\0') {
+		return 1;
+	}
+
+	// create pipes for each command
+	int **pipes = malloc((num_commands - 1) * sizeof(int *));
+	for (int i = 0; i < num_commands - 1; i++) {
+		pipes[i] =
+			malloc(2 * sizeof(int)); // pipes[i][0] = in, pipes[i][1] = out
+		if (pipe(pipes[i]) == -1) {
+			perror("pipe");
+			return 0;
+		}
+	}
+
+	// execute commands in the pipeline
+	for (int i = 0; i < num_commands - 1; i++) {
+		int input_fd = (i == 0) ? STDIN_FILENO : pipes[i - 1][0];
+		int output_fd = pipes[i][1];
+
+		lush_execute_command(commands[i], input_fd, output_fd);
+		close(output_fd); // no longer need to write to this pipe
+	}
+
+	// execute last or only command
+	int input_fd =
+		(num_commands > 1) ? pipes[num_commands - 2][0] : STDIN_FILENO;
+	int output_fd = STDOUT_FILENO;
+	lush_execute_command(commands[num_commands - 1], input_fd, output_fd);
+
+	// close pipes
+	for (int i = 0; i < num_commands - 1; i++) {
+		close(pipes[i][0]);
+		close(pipes[i][1]);
+		free(pipes[i]);
+	}
+	free(pipes);
+	return 1;
+}
+
+void lush_execute_command(char **args, int input_fd, int output_fd) {
+	// create child
+	pid_t pid;
+	pid_t wpid;
+	int status;
+
+	if ((pid = fork()) == 0) {
+		// child process content
+
+		// redirect in and out fd's if needed
+		if (input_fd != STDIN_FILENO) {
+			dup2(input_fd, STDIN_FILENO);
+			close(input_fd);
+		}
+
+		if (output_fd != STDOUT_FILENO) {
+			dup2(output_fd, STDOUT_FILENO);
+			close(output_fd);
+		}
+
+		// execute the command
+		if (execvp(args[0], args) == -1) {
+			perror("execvp");
+			exit(EXIT_FAILURE);
+		}
+	} else if (pid < 0) {
+		// forking failed
+		perror("fork");
+		exit(EXIT_FAILURE);
+	} else {
+		// parent process
+		do {
+			wpid = waitpid(pid, &status, WUNTRACED);
+		} while (!WIFEXITED(status) && !WIFSIGNALED(status));
+	}
+}
+
+int lush_run(char ***commands, int num_commands) {
+	if (commands[0][0] == NULL) {
+		// no command given
+		return 1;
+	}
+
+	// check shell builtins
+	for (int i = 0; i < lush_num_builtins(); i++) {
+		if (strcmp(commands[0][0], builtin_strs[i]) == 0) {
+			return ((*builtin_func[i])(commands));
+		}
+	}
+
+	return lush_execute_pipeline(commands, num_commands);
+}
+
+int main() {
+	int status = 0;
+	while (true) {
+		// Prompt
+		char *cwd = getcwd(NULL, 0);
+		printf("%s _> ", cwd);
+
+		char *line = lush_read_line();
+		char **commands = lush_split_pipes(line);
+		char ***args = lush_split_args(commands, &status);
+		if (status == -1) {
+			fprintf(stderr, "lush: Expected end of quoted string\n");
+		} else if (lush_run(args, status) == 0) {
+			exit(1);
+		}
+
+		for (int i = 0; args[i]; i++) {
+			free(args[i]);
+		}
+		free(args);
+		free(commands);
+		free(line);
+		free(cwd);
+	}
+}
diff --git a/src/lush.h b/src/lush.h
new file mode 100644
index 0000000..65846b0
--- /dev/null
+++ b/src/lush.h
@@ -0,0 +1,37 @@
+/*
+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.
+*/
+
+#ifndef LUSH_H
+#define LUSH_H
+
+int lush_cd(char ***args);
+int lush_help(char ***args);
+int lush_exit(char ***args);
+int lush_time(char ***args);
+
+int lush_num_builtins();
+
+int lush_run(char ***commands, int num_commands);
+
+char *lush_read_line();
+char **lush_split_pipes(char *line);
+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);
+
+#endif // LUSH_H