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Commit 966b801e authored by Joey Le's avatar Joey Le
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Fixed dshlib.c

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Assignment-06/starter/dshlib.c
+ 82
− 147
View file @ 966b801e
...@@ -6,10 +6,11 @@ ...@@ -6,10 +6,11 @@
#include <unistd.h> #include <unistd.h>
#include <fcntl.h> #include <fcntl.h>
#include <sys/wait.h> #include <sys/wait.h>
#include <errno.h>
#include "dshlib.h" #include "dshlib.h"
// Function to build a command buffer from a command line
int build_cmd_buff(char *cmd_line, cmd_buff_t *cmd_buff) { int build_cmd_buff(char *cmd_line, cmd_buff_t *cmd_buff) {
if (cmd_line == NULL || cmd_buff == NULL) { if (cmd_line == NULL || cmd_buff == NULL) {
return ERR_CMD_OR_ARGS_TOO_BIG; return ERR_CMD_OR_ARGS_TOO_BIG;
...@@ -29,7 +30,7 @@ int build_cmd_buff(char *cmd_line, cmd_buff_t *cmd_buff) { ...@@ -29,7 +30,7 @@ int build_cmd_buff(char *cmd_line, cmd_buff_t *cmd_buff) {
char quote_char = '\0'; char quote_char = '\0';
while (*ptr != '\0') { while (*ptr != '\0') {
if ((isspace((unsigned char)*ptr) && !in_quotes)) { if ((isspace((unsigned char)*ptr) && !in_quotes) {
if (arg_start != NULL) { if (arg_start != NULL) {
*ptr = '\0'; *ptr = '\0';
cmd_buff->argv[cmd_buff->argc++] = arg_start; cmd_buff->argv[cmd_buff->argc++] = arg_start;
...@@ -59,18 +60,11 @@ int build_cmd_buff(char *cmd_line, cmd_buff_t *cmd_buff) { ...@@ -59,18 +60,11 @@ int build_cmd_buff(char *cmd_line, cmd_buff_t *cmd_buff) {
cmd_buff->argv[cmd_buff->argc] = NULL; cmd_buff->argv[cmd_buff->argc] = NULL;
// Debugging output to verify parsing
// printf("Parsed command:\n");
// for (int i = 0; i < cmd_buff->argc; i++) {
// printf(" argv[%d]: %s\n", i, cmd_buff->argv[i]);
// }
return OK; return OK;
} }
char *trim_whitespace(char *str) { //Had to make a new function for readability // Function to trim whitespace from a string
char *trim_whitespace(char *str) {
char *end; char *end;
while (isspace((unsigned char)*str)) str++; while (isspace((unsigned char)*str)) str++;
...@@ -82,15 +76,13 @@ char *trim_whitespace(char *str) { //Had to make a new function for readability ...@@ -82,15 +76,13 @@ char *trim_whitespace(char *str) { //Had to make a new function for readability
end = str + strlen(str) - 1; end = str + strlen(str) - 1;
while (end > str && isspace((unsigned char)*end)) end--; while (end > str && isspace((unsigned char)*end)) end--;
// new null terminator // New null terminator
*(end + 1) = '\0'; *(end + 1) = '\0';
return str; return str;
} }
// Function to parse a pipeline of commands
int parse_pipeline(const char *cmd_line, command_list_t *clist) { int parse_pipeline(const char *cmd_line, command_list_t *clist) {
if (cmd_line == NULL || clist == NULL) { if (cmd_line == NULL || clist == NULL) {
return ERR_CMD_OR_ARGS_TOO_BIG; return ERR_CMD_OR_ARGS_TOO_BIG;
...@@ -100,7 +92,8 @@ int parse_pipeline(const char *cmd_line, command_list_t *clist) { ...@@ -100,7 +92,8 @@ int parse_pipeline(const char *cmd_line, command_list_t *clist) {
if (line_copy == NULL) { if (line_copy == NULL) {
return ERR_MEMORY; return ERR_MEMORY;
} }
//Parsing using pipe.
// Parsing using pipe
clist->num = 0; clist->num = 0;
char *saveptr; char *saveptr;
char *command = strtok_r(line_copy, "|", &saveptr); char *command = strtok_r(line_copy, "|", &saveptr);
...@@ -126,23 +119,12 @@ int parse_pipeline(const char *cmd_line, command_list_t *clist) { ...@@ -126,23 +119,12 @@ int parse_pipeline(const char *cmd_line, command_list_t *clist) {
return OK; return OK;
} }
// Function to execute a pipeline of commands
int execute_pipeline(command_list_t *clist) { int execute_pipeline(command_list_t *clist) {
int num_commands = clist->num; int num_commands = clist->num;
int pipefd[2 * (num_commands - 1)]; int pipefd[2 * (num_commands - 1)];
pid_t pids[num_commands]; pid_t pids[num_commands];
// for (int i = 0; i < clist->num; i++) {
// printf("Command %d:\n", i);
// for (int j = 0; clist->commands[i].argv[j] != NULL; j++) {
// printf(" argv[%d]: %s\n", j, clist->commands[i].argv[j]);
// }
// }
for (int i = 0; i < num_commands - 1; i++) { for (int i = 0; i < num_commands - 1; i++) {
if (pipe(pipefd + 2 * i) == -1) { if (pipe(pipefd + 2 * i) == -1) {
perror("pipe"); perror("pipe");
...@@ -159,7 +141,7 @@ int execute_pipeline(command_list_t *clist) { ...@@ -159,7 +141,7 @@ int execute_pipeline(command_list_t *clist) {
} }
if (pids[i] == 0) { // Child process if (pids[i] == 0) { // Child process
// if not first moves input // Redirect input if not the first command
if (i > 0) { if (i > 0) {
if (dup2(pipefd[2 * (i - 1)], STDIN_FILENO) == -1) { if (dup2(pipefd[2 * (i - 1)], STDIN_FILENO) == -1) {
perror("dup2 stdin"); perror("dup2 stdin");
...@@ -175,7 +157,7 @@ int execute_pipeline(command_list_t *clist) { ...@@ -175,7 +157,7 @@ int execute_pipeline(command_list_t *clist) {
} }
} }
// Close all pipe file descriptors. Very important stuff // Close all pipe file descriptors
for (int j = 0; j < 2 * (num_commands - 1); j++) { for (int j = 0; j < 2 * (num_commands - 1); j++) {
close(pipefd[j]); close(pipefd[j]);
} }
...@@ -187,12 +169,12 @@ int execute_pipeline(command_list_t *clist) { ...@@ -187,12 +169,12 @@ int execute_pipeline(command_list_t *clist) {
} }
} }
// Closes all pipe // Close all pipe file descriptors in the parent
for (int i = 0; i < 2 * (num_commands - 1); i++) { for (int i = 0; i < 2 * (num_commands - 1); i++) {
close(pipefd[i]); close(pipefd[i]);
} }
// waitpid so everyhting is smooth // Wait for all child processes to finish
for (int i = 0; i < num_commands; i++) { for (int i = 0; i < num_commands; i++) {
int status; int status;
waitpid(pids[i], &status, 0); waitpid(pids[i], &status, 0);
...@@ -206,97 +188,55 @@ int execute_pipeline(command_list_t *clist) { ...@@ -206,97 +188,55 @@ int execute_pipeline(command_list_t *clist) {
return OK; return OK;
} }
static void start_server() { // Main loop for executing local commands
int listen_socket; int exec_local_cmd_loop() {
int ret; char cmd_buff[SH_CMD_MAX];
int rc = OK;
}
/****
**** FOR REMOTE SHELL USE YOUR SOLUTION FROM SHELL PART 3 HERE
**** THE MAIN FUNCTION CALLS THIS ONE AS ITS ENTRY POINT TO
**** EXECUTE THE SHELL LOCALLY
****
*/
/*
* 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
* use fgets to accept user input.
*
* while(1){
* printf("%s", SH_PROMPT);
* if (fgets(cmd_buff, ARG_MAX, stdin) == NULL){
* printf("\n");
* break;
* }
* //remove the trailing \n from cmd_buff
* cmd_buff[strcspn(cmd_buff,"\n")] = '\0';
*
* //IMPLEMENT THE REST OF THE REQUIREMENTS
* }
*
* Also, use the constants in the dshlib.h in this code.
* SH_CMD_MAX maximum buffer size for user input
* EXIT_CMD constant that terminates the dsh program
* SH_PROMPT the shell prompt
* OK the command was parsed properly
* WARN_NO_CMDS the user command was empty
* ERR_TOO_MANY_COMMANDS too many pipes used
* ERR_MEMORY dynamic memory management failure
*
* errors returned
* OK No error
* ERR_MEMORY Dynamic memory management failure
* WARN_NO_CMDS No commands parsed
* ERR_TOO_MANY_COMMANDS too many pipes used
*
* console messages
* CMD_WARN_NO_CMD print on WARN_NO_CMDS
* CMD_ERR_PIPE_LIMIT print on ERR_TOO_MANY_COMMANDS
* CMD_ERR_EXECUTE print on execution failure of external command
*
* Standard Library Functions You Might Want To Consider Using (assignment 1+)
* malloc(), free(), strlen(), fgets(), strcspn(), printf()
*
* Standard Library Functions You Might Want To Consider Using (assignment 2+)
* fork(), execvp(), exit(), chdir()
*/
int exec_remote_cmd_loop(char *address, int port) {
char cmd_buff[RDSH_COMM_BUFF_SZ];
char rsp_buff[RDSH_COMM_BUFF_SZ];
int cli_socket;
ssize_t recv_bytes;
int is_eof;
// Connect to the server
cli_socket = start_client(address, port);
if (cli_socket < 0) {
perror("start client");
return client_cleanup(cli_socket, NULL, NULL, ERR_RDSH_CLIENT);
}
while (1) { while (1) {
printf("rsh> "); printf("%s", SH_PROMPT);
if (!fgets(cmd_buff, RDSH_COMM_BUFF_SZ, stdin)) {
break; // Exit on input error or EOF if (fgets(cmd_buff, SH_CMD_MAX, stdin) == NULL) {
printf("\n");
break;
} }
// Remove the newline character from the command cmd_buff[strcspn(cmd_buff, "\n")] = '\0';
size_t cmd_len = strlen(cmd_buff);
if (cmd_len > 0 && cmd_buff[cmd_len - 1] == '\n') { if (strlen(cmd_buff) == 0) {
cmd_buff[cmd_len - 1] = '\0'; printf("%s\n", CMD_WARN_NO_CMD);
rc = WARN_NO_CMDS;
continue;
} }
// Handle local commands (e.g., cd, exit) if (strstr(cmd_buff, "|") != NULL) {
if (strncmp(cmd_buff, "cd", 2) == 0) { command_list_t cmd_list;
// Handle cd locally if (parse_pipeline(cmd_buff, &cmd_list) != OK) {
fprintf(stderr, "%s\n", CMD_ERR_PIPE_LIMIT);
rc = ERR_TOO_MANY_COMMANDS;
continue;
}
rc = execute_pipeline(&cmd_list);
// Free memory for each command's buffer
for (int i = 0; i < cmd_list.num; i++) {
free(cmd_list.commands[i]._cmd_buffer);
}
} else {
cmd_buff_t cmd; cmd_buff_t cmd;
if (build_cmd_buff(cmd_buff, &cmd) != OK) { if (build_cmd_buff(cmd_buff, &cmd) != OK) {
fprintf(stderr, "%s\n", CMD_ERR_PIPE_LIMIT); fprintf(stderr, "%s\n", CMD_ERR_PIPE_LIMIT);
rc = ERR_MEMORY;
continue; 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) { if (cmd.argc == 1) {
chdir(getenv("HOME")); chdir(getenv("HOME"));
} else if (cmd.argc == 2) { } else if (cmd.argc == 2) {
...@@ -308,35 +248,30 @@ static void start_server() { ...@@ -308,35 +248,30 @@ static void start_server() {
} }
free(cmd._cmd_buffer); free(cmd._cmd_buffer);
continue; continue;
} else if (strncmp(cmd_buff, "exit", 4) == 0) {
break; // Exit the remote shell
} }
// Send the command to the server pid_t pid = fork();
ssize_t sent_bytes = send(cli_socket, cmd_buff, strlen(cmd_buff), 0); if (pid < 0) {
if (sent_bytes < 0) { perror("fork failed");
perror("send"); rc = ERR_MEMORY;
return client_cleanup(cli_socket, NULL, NULL, ERR_RDSH_COMMUNICATION); } else if (pid == 0) {
} execvp(cmd.argv[0], cmd.argv);
perror("execvp failed");
exit(EXIT_FAILURE);
} else {
int status;
wait(&status);
// Receive the server's response if (WIFEXITED(status)) {
is_eof = 0; if (WEXITSTATUS(status) != 0) {
while ((recv_bytes = recv(cli_socket, rsp_buff, RDSH_COMM_BUFF_SZ, 0)) > 0) { fprintf(stderr, "Command failed with exit code %d\n", WEXITSTATUS(status));
printf("%.*s", (int)recv_bytes, rsp_buff); }
if (rsp_buff[recv_bytes - 1] == RDSH_EOF_CHAR) {
is_eof = 1;
break;
} }
} }
if (recv_bytes < 0) { free(cmd._cmd_buffer);
perror("recv");
return client_cleanup(cli_socket, NULL, NULL, ERR_RDSH_COMMUNICATION);
} else if (recv_bytes == 0) {
printf("Server closed the connection\n");
break;
} }
} }
return client_cleanup(cli_socket, NULL, NULL, OK); return rc;
} }
\ No newline at end of file
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