diff --git a/Assignment-05/starter/dshlib.c b/Assignment-05/starter/dshlib.c
index 0e6738ed007037b9f293051f058931ad8cb98ced..4e869d1b3f8c2ad4b94aeb2121f069b12fe21b27 100644
--- a/Assignment-05/starter/dshlib.c
+++ b/Assignment-05/starter/dshlib.c
@@ -9,6 +9,174 @@
#include "dshlib.h"
+int build_cmd_buff(char *cmd_line, cmd_buff_t *cmd_buff) {
+ if (cmd_line == NULL || cmd_buff == NULL) {
+ return ERR_CMD_OR_ARGS_TOO_BIG;
+ }
+
+ char *original_line = strdup(cmd_line);
+ if (original_line == NULL) {
+ return ERR_MEMORY;
+ }
+
+ char *trimmed_line = original_line;
+ while (*trimmed_line == ' ') {
+ trimmed_line++;
+ }
+
+ size_t len = strlen(trimmed_line);
+ while (len > 0 && trimmed_line[len - 1] == ' ') {
+ trimmed_line[--len] = '\0';
+ }
+
+ cmd_buff->argc = 0;
+ cmd_buff->_cmd_buffer = original_line;
+
+ char *saveptr1;
+ char *token = strtok_r(trimmed_line, " ", &saveptr1);
+
+ while (token != NULL && cmd_buff->argc < CMD_ARGV_MAX) {
+ if (token[0] == '"' || token[0] == '\'') {
+ char *end_quote = strchr(token + 1, token[0]);
+ if (end_quote != NULL) {
+ *end_quote = '\0';
+ cmd_buff->argv[cmd_buff->argc++] = token + 1;
+ token = strtok_r(NULL, " ", &saveptr1);
+ continue;
+ }
+ }
+ cmd_buff->argv[cmd_buff->argc++] = token;
+ token = strtok_r(NULL, " ", &saveptr1);
+ }
+ cmd_buff->argv[cmd_buff->argc] = NULL;
+
+ return OK;
+}
+
+
+
+
+int execute_pipeline(command_list_t *cmd_list) {
+ int num_commands = cmd_list->num;
+ int pipefd[2];
+ int prev_pipe_read = -1;
+ pid_t pids[num_commands];
+
+ for (int i = 0; i < num_commands; i++) {
+ if (i < num_commands - 1) {
+ if (pipe(pipefd) == -1) {
+ perror("pipe");
+ return ERR_MEMORY;
+ }
+ }
+
+ pids[i] = fork();
+ if (pids[i] == -1) {
+ perror("fork");
+ return ERR_MEMORY;
+ }
+
+ if (pids[i] == 0) {
+ if (prev_pipe_read != -1) {
+ dup2(prev_pipe_read, STDIN_FILENO);
+ close(prev_pipe_read);
+ }
+
+ if (i < num_commands - 1) {
+ dup2(pipefd[1], STDOUT_FILENO);
+ close(pipefd[1]);
+ close(pipefd[0]);
+ }
+
+ cmd_buff_t *cmd = &cmd_list->commands[i];
+ execvp(cmd->exe, cmd->argv);
+ perror("execvp");
+ exit(EXIT_FAILURE);
+ } else {
+ if (prev_pipe_read != -1) {
+ close(prev_pipe_read);
+ }
+
+ if (i < num_commands - 1) {
+ prev_pipe_read = pipefd[0];
+ close(pipefd[1]);
+ }
+ }
+ }
+
+ for (int i = 0; i < num_commands; i++) {
+ waitpid(pids[i], NULL, 0);
+ }
+
+ return OK;
+}
+
+int parse_pipeline(char *cmd_line, command_list_t *clist) {
+ if (cmd_line == NULL || clist == NULL) {
+ return ERR_CMD_OR_ARGS_TOO_BIG;
+ }
+
+ char *original_line = strdup(cmd_line);
+ if (original_line == NULL) {
+ return ERR_MEMORY;
+ }
+
+ char *trimmed_line = original_line;
+ while (*trimmed_line == ' ') {
+ trimmed_line++;
+ }
+ size_t len = strlen(trimmed_line);
+ while (len > 0 && trimmed_line[len - 1] == ' ') {
+ trimmed_line[--len] = '\0';
+ }
+
+ int command_count = 0;
+ char *saveptr1, *saveptr2;
+ char *command = strtok_r(trimmed_line, PIPE_STRING, &saveptr1);
+
+ while (command != NULL && command_count < CMD_MAX) {
+ memset(&clist->commands[command_count], 0, sizeof(command_t));
+
+ char *token = strtok_r(command, " ", &saveptr2);
+ if (token != NULL) {
+ if (strlen(token) >= EXE_MAX) {
+ free(original_line);
+ return ERR_CMD_OR_ARGS_TOO_BIG;
+ }
+ strcpy(clist->commands[command_count].exe, token);
+
+ int arg_count = 0;
+ while ((token = strtok_r(NULL, " ", &saveptr2)) != NULL) {
+ if (arg_count >= ARG_MAX - 1) {
+ free(original_line);
+ return ERR_CMD_OR_ARGS_TOO_BIG;
+ }
+ if (strlen(token) >= ARG_MAX) {
+ free(original_line);
+ return ERR_CMD_OR_ARGS_TOO_BIG;
+ }
+ strcpy(clist->commands[command_count].args[arg_count], token);
+ arg_count++;
+ }
+ clist->commands[command_count].args[arg_count] = NULL;
+ }
+
+ command_count++;
+ command = strtok_r(NULL, PIPE_STRING, &saveptr1);
+ }
+
+ if (command != NULL) {
+ // Too many commands
+ free(original_line);
+ return ERR_TOO_MANY_COMMANDS;
+ }
+
+ clist->num = command_count;
+ free(original_line);
+ return OK;
+}
+
+
/*
* Implement your exec_local_cmd_loop function by building a loop that prompts the
* user for input. Use the SH_PROMPT constant from dshlib.h and then
@@ -52,8 +220,90 @@
* Standard Library Functions You Might Want To Consider Using (assignment 2+)
* fork(), execvp(), exit(), chdir()
*/
-int exec_local_cmd_loop()
-{
-
- return OK;
+
+ int exec_local_cmd_loop() {
+ char cmd_buff[SH_CMD_MAX];
+ int rc = OK;
+
+ while (1) {
+ printf("%s", SH_PROMPT);
+
+ if (fgets(cmd_buff, SH_CMD_MAX, stdin) == NULL) {
+ printf("\n");
+ break;
+ }
+
+ cmd_buff[strcspn(cmd_buff, "\n")] = '\0';
+
+ if (strlen(cmd_buff) == 0) {
+ printf("%s\n", CMD_WARN_NO_CMD);
+ rc = WARN_NO_CMDS;
+ continue;
+ }
+
+ if (strstr(cmd_buff, "|") != NULL) {
+ command_list_t cmd_list;
+ if (parse_pipeline(cmd_buff, &cmd_list) != OK) {
+ fprintf(stderr, "%s\n", CMD_ERR_PIPE_LIMIT);
+ rc = ERR_TOO_MANY_COMMANDS;
+ continue;
+ }
+
+ if (execute_pipeline(&cmd_list) != OK) {
+ fprintf(stderr, "%s\n", CMD_ERR_EXECUTE);
+ rc = ERR_MEMORY;
+ }
+
+ free_command_list(&cmd_list);
+ } else {
+ cmd_buff_t cmd;
+ if (build_cmd_buff(cmd_buff, &cmd) != OK) {
+ fprintf(stderr, "%s\n", CMD_ERR_EXECUTE);
+ rc = ERR_MEMORY;
+ continue;
+ }
+
+ if (strcmp(cmd.argv[0], EXIT_CMD) == 0) {
+ free(cmd._cmd_buffer);
+ break;
+ }
+
+ if (strcmp(cmd.argv[0], "cd") == 0) {
+ if (cmd.argc == 1) {
+ chdir(getenv("HOME"));
+ } else if (cmd.argc == 2) {
+ if (chdir(cmd.argv[1]) != 0) {
+ perror("cd");
+ }
+ } else {
+ fprintf(stderr, "%s\n", CMD_ERR_PIPE_LIMIT);
+ }
+ free(cmd._cmd_buffer);
+ continue;
+ }
+
+ pid_t pid = fork();
+ if (pid < 0) {
+ perror("fork failed");
+ rc = ERR_MEMORY;
+ } else if (pid == 0) {
+ execvp(cmd.argv[0], cmd.argv);
+ perror("execvp failed");
+ exit(EXIT_FAILURE);
+ } else {
+ int status;
+ wait(&status);
+
+ if (WIFEXITED(status)) {
+ if (WEXITSTATUS(status) != 0) {
+ fprintf(stderr, "Command failed with exit code %d\n", WEXITSTATUS(status));
+ }
+ }
+ }
+
+ free(cmd._cmd_buffer);
+ }
+ }
+
+ return rc;
}