submit

4-Shell-Part2/bats/assignment_tests.sh

+#!/usr/bin/env bats
+
+############################ DO NOT EDIT THIS FILE #####################################
+# File: assignement_tests.sh
+# 
+# DO NOT EDIT THIS FILE
+#
+# Add/Edit Student tests in student_tests.sh
+# 
+# All tests in this file must pass - it is used as part of grading!
+########################################################################################
+
+@test "Change directory" {
+    current=$(pwd)
+
+    cd /tmp
+    mkdir -p dsh-test
+
+    run "${current}/dsh" <<EOF                
+cd dsh-test
+pwd
+EOF
+
+    # Strip all whitespace (spaces, tabs, newlines) from the output
+    stripped_output=$(echo "$output" | tr -d '[:space:]')
+
+    # Expected output with all whitespace removed for easier matching
+    expected_output="/tmp/dsh-testdsh2>dsh2>dsh2>cmdloopreturned0"
+
+    # These echo commands will help with debugging and will only print
+    #if the test fails
+    echo "Captured stdout:" 
+    echo "Output: $output"
+    echo "Exit Status: $status"
+    echo "${stripped_output} -> ${expected_output}"
+
+    # Check exact match
+    [ "$stripped_output" = "$expected_output" ]
+
+    # Assertions
+    [ "$status" -eq 0 ]
+}
+
+@test "Change directory - no args" {
+    current=$(pwd)
+
+    cd /tmp
+    mkdir -p dsh-test
+
+    run "${current}/dsh" <<EOF                
+cd
+pwd
+EOF
+
+    # Strip all whitespace (spaces, tabs, newlines) from the output
+    stripped_output=$(echo "$output" | tr -d '[:space:]')
+
+    # Expected output with all whitespace removed for easier matching
+    expected_output="/tmpdsh2>dsh2>dsh2>cmdloopreturned0"
+
+    # These echo commands will help with debugging and will only print
+    #if the test fails
+    echo "Captured stdout:" 
+    echo "Output: $output"
+    echo "Exit Status: $status"
+    echo "${stripped_output} -> ${expected_output}"
+
+    # Check exact match
+    [ "$stripped_output" = "$expected_output" ]
+
+    # Assertions
+    [ "$status" -eq 0 ]
+}
+
+
+@test "Which which ... which?" {
+    run "./dsh" <<EOF                
+which which
+EOF
+
+    # Strip all whitespace (spaces, tabs, newlines) from the output
+    stripped_output=$(echo "$output" | tr -d '[:space:]')
+
+    # Expected output with all whitespace removed for easier matching
+    expected_output="/usr/bin/whichdsh2>dsh2>cmdloopreturned0"
+
+    # These echo commands will help with debugging and will only print
+    #if the test fails
+    echo "Captured stdout:" 
+    echo "Output: $output"
+    echo "Exit Status: $status"
+    echo "${stripped_output} -> ${expected_output}"
+
+    # Check exact match
+    [ "$stripped_output" = "$expected_output" ]
+}
+
+@test "It handles quoted spaces" {
+    run "./dsh" <<EOF                
+   echo " hello     world     " 
+EOF
+
+    # Strip all whitespace (spaces, tabs, newlines) from the output
+    stripped_output=$(echo "$output" | tr -d '\t\n\r\f\v')
+
+    # Expected output with all whitespace removed for easier matching
+    expected_output=" hello     world     dsh2> dsh2> cmd loop returned 0"
+
+    # These echo commands will help with debugging and will only print
+    #if the test fails
+    echo "Captured stdout:" 
+    echo "Output: $output"
+    echo "Exit Status: $status"
+    echo "actual:   '${stripped_output}'"
+    echo "expected: '${expected_output}'"
+
+    # Check exact match
+    [ "$stripped_output" = "$expected_output" ]
+}
\ No newline at end of file

4-Shell-Part2/bats/student_tests.sh

+#!/usr/bin/env bats
+
+# File: student_tests.sh
+# 
+# Create your unit tests suit in this file
+
+@test "Example: check ls runs without errors" {
+    run ./dsh <<EOF                
+ls
+EOF
+
+    # Assertions
+    [ "$status" -eq 0 ]
+}

4-Shell-Part2/dragon.c

+#include <stdio.h>
+
+// EXTRA CREDIT - print the drexel dragon from the readme.md
+extern void print_dragon(){
+  // TODO implement 
+}

4-Shell-Part2/dsh_cli.c

+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "dshlib.h"
+
+/* DO NOT EDIT
+ * main() logic moved to exec_local_cmd_loop() in dshlib.c
+*/
+int main(){
+  int rc = exec_local_cmd_loop();
+  printf("cmd loop returned %d\n", rc);
+}
\ No newline at end of file

4-Shell-Part2/dshlib.c

+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include "dshlib.h"
+
+/*
+ * 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()
+ */
+
+ void printDragon(){
+    const char dragon[39][103] = {
+"                                                                        @%%%%                       \n",                       
+"                                                                     %%%%%%                         \n",                         
+"                                                                    %%%%%%                          \n",                          
+"                                                                 % %%%%%%%           @              \n",              
+"                                                                %%%%%%%%%%        %%%%%%%           \n",           
+"                                       %%%%%%%  %%%%@         %%%%%%%%%%%%@    %%%%%%  @%%%%        \n",        
+"                                  %%%%%%%%%%%%%%%%%%%%%%      %%%%%%%%%%%%%%%%%%%%%%%%%%%%          \n",          
+"                                %%%%%%%%%%%%%%%%%%%%%%%%%%   %%%%%%%%%%%% %%%%%%%%%%%%%%%           \n",           
+"                               %%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%     %%%            \n",            
+"                             %%%%%%%%%%%%%%%%%%%%%%%%%%%%@ @%%%%%%%%%%%%%%%%%%        %%            \n",            
+"                            %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%                \n",                
+"                            %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%              \n",              
+"                            %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%@%%%%%%@              \n",              
+"      %%%%%%%%@           %%%%%%%%%%%%%%%%        %%%%%%%%%%%%%%%%%%%%%%%%%%      %%                \n",                
+"    %%%%%%%%%%%%%         %%@%%%%%%%%%%%%           %%%%%%%%%%% %%%%%%%%%%%%      @%                \n",                
+"  %%%%%%%%%%   %%%        %%%%%%%%%%%%%%            %%%%%%%%%%%%%%%%%%%%%%%%                        \n",                        
+" %%%%%%%%%       %         %%%%%%%%%%%%%             %%%%%%%%%%%%@%%%%%%%%%%%                       \n",                   
+"%%%%%%%%%@                % %%%%%%%%%%%%%            @%%%%%%%%%%%%%%%%%%%%%%%%%                     \n",              
+"%%%%%%%%@                 %%@%%%%%%%%%%%%            @%%%%%%%%%%%%%%%%%%%%%%%%%%%%                  \n",         
+"%%%%%%%@                   %%%%%%%%%%%%%%%           %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%              \n",    
+"%%%%%%%%%%                  %%%%%%%%%%%%%%%          %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%      %%%%  \n",
+"%%%%%%%%%@                   @%%%%%%%%%%%%%%         %%%%%%%%%%%%@ %%%% %%%%%%%%%%%%%%%%%   %%%%%%%%\n",
+"%%%%%%%%%%                  %%%%%%%%%%%%%%%%%        %%%%%%%%%%%%%      %%%%%%%%%%%%%%%%%% %%%%%%%%%\n",
+"%%%%%%%%%@%%@                %%%%%%%%%%%%%%%%@       %%%%%%%%%%%%%%     %%%%%%%%%%%%%%%%%%%%%%%%  %%\n",
+" %%%%%%%%%%                  % %%%%%%%%%%%%%%@        %%%%%%%%%%%%%%   %%%%%%%%%%%%%%%%%%%%%%%%%% %%\n",
+"  %%%%%%%%%%%%  @           %%%%%%%%%%%%%%%%%%        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  %%% \n",
+"   %%%%%%%%%%%%% %%  %  %@ %%%%%%%%%%%%%%%%%%          %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%    %%% \n",
+"    %%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%           @%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%    %%%%%%% \n",
+"     %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%              %%%%%%%%%%%%%%%%%%%%%%%%%%%%        %%%   \n",
+"      @%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%                  %%%%%%%%%%%%%%%%%%%%%%%%%               \n",
+"        %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%                      %%%%%%%%%%%%%%%%%%%  %%%%%%%          \n",
+"           %%%%%%%%%%%%%%%%%%%%%%%%%%                           %%%%%%%%%%%%%%%  @%%%%%%%%%         \n",
+"              %%%%%%%%%%%%%%%%%%%%           @%@%                  @%%%%%%%%%%%%%%%%%%   %%%        \n",
+"                  %%%%%%%%%%%%%%%        %%%%%%%%%%                    %%%%%%%%%%%%%%%    %         \n",
+"                %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%                      %%%%%%%%%%%%%%            \n",
+"                %%%%%%%%%%%%%%%%%%%%%%%%%%  %%%% %%%                      %%%%%%%%%%  %%%@          \n",
+"                     %%%%%%%%%%%%%%%%%%% %%%%%% %%                          %%%%%%%%%%%%%@          \n",
+"                                                                                 %%%%%%%@           \n"
+    };
+
+
+    for (int i = 0; i < sizeof(dragon) / sizeof(dragon[0]); i++) {
+        for (int j = 0; j < sizeof(dragon[0]) / sizeof(dragon[0][0]); j++) {
+            if (dragon[i][j] == 0) break;
+            putchar((char)dragon[i][j]);
+        }
+    }
+}
+
+int exec_local_cmd_loop()
+{
+    char *cmd_buff;
+    int rc = 0;
+    cmd_buff_t cmd;
+
+    // TODO IMPLEMENT MAIN LOOP
+
+    // TODO IMPLEMENT parsing input to cmd_buff_t *cmd_buff
+    cmd_buff = malloc(SH_CMD_MAX);
+    if (!cmd_buff) return ERR_MEMORY;
+
+    while(1) {
+        printf("%s", SH_PROMPT);
+        
+        if (fgets(cmd_buff, ARG_MAX, stdin) == NULL) {
+            printf("\n");
+            break;
+        }
+
+        // Remove trailing newline
+        cmd_buff[strcspn(cmd_buff, "\n")] = '\0';
+
+        // Skip empty commands
+        if (strlen(cmd_buff) == 0) {
+            printf(CMD_WARN_NO_CMD);
+            continue;
+        }
+
+        // Parse command and arguments
+        char *exe = strtok(cmd_buff, " ");
+        char *args = strtok(NULL, "");
+
+
+        if (exe) {
+            cmd.argc = 0;
+            cmd.argv[cmd.argc++] = exe;
+
+            if (args) {
+                char* lastChar = args + strlen(args) - 1;
+
+                // removing space after the
+                while (*lastChar == ' ') {
+                    *lastChar = '\0';
+                    lastChar--;
+                }
+
+                char *argsNoQuotes = malloc(ARG_MAX);
+                int numQuotes = 0;
+                int argQuoteLength = strlen(args);
+                int argLength = 0;
+                
+                while (*args != '\0') {
+                    if (*args == '\"') {
+                        numQuotes++;
+                        args++;
+                    } else {
+                        *argsNoQuotes = *args;
+                        argLength++;
+                        args++;
+                        argsNoQuotes++;
+                    }
+                }
+    
+                argsNoQuotes -= argLength;
+                cmd.argv[cmd.argc++] = argsNoQuotes;
+            }
+
+            else {
+                cmd.argv[cmd.argc] = NULL;
+            }
+        }
+
+
+        // TODO IMPLEMENT if built-in command, execute builtin logic for exit, cd (extra credit: dragon)
+        // the cd command should chdir to the provided directory; if no directory is provided, do nothing
+
+        if (strcmp(cmd.argv[0], EXIT_CMD) == 0) {
+            break;
+
+        } else if (strcmp(cmd.argv[0], "cd") == 0) {
+            if (cmd.argv[1]) {
+                if (chdir(cmd.argv[1]) != 0) {
+                    perror("cd");
+                    rc = ERR_CMD_ARGS_BAD;
+                }
+            }
+            continue;
+
+        } else if (strcmp(cmd.argv[0], "dragon") == 0) {
+            printDragon();
+            continue;
+        }
+        else if (strcmp(cmd.argv[0], "rc") == 0) {
+            printf("%d\n", rc);
+            continue;
+        }
+        // TODO IMPLEMENT if not built-in command, fork/exec as an external command
+        // for example, if the user input is "ls -l", you would fork/exec the command "ls" with the arg "-l"
+
+        pid_t pid = fork();
+        
+        if (pid < 0) {
+            // printf(CMD_ERR_EXECUTE);
+            return ERR_MEMORY;
+        } else if (pid == 0) {
+            execvp(cmd.argv[0], cmd.argv);
+            // printf(CMD_ERR_EXECUTE);
+            exit(errno);
+        } else {
+            // parent process
+            wait(&rc);
+            if (WIFEXITED(rc)) {
+                rc = WEXITSTATUS(rc);  // Store last return code
+            } else {
+                rc = ERR_EXEC_CMD;
+            }
+            // wait(NULL);
+        }
+    }
+}

4-Shell-Part2/dshlib.h

+#ifndef __DSHLIB_H__
+    #define __DSHLIB_H__
+
+
+//Constants for command structure sizes
+#define EXE_MAX 64
+#define ARG_MAX 256
+#define CMD_MAX 8
+#define CMD_ARGV_MAX (CMD_MAX + 1)
+// Longest command that can be read from the shell
+#define SH_CMD_MAX EXE_MAX + ARG_MAX
+
+typedef struct cmd_buff
+{
+    int  argc;
+    char *argv[CMD_ARGV_MAX];
+    char *_cmd_buffer;
+} cmd_buff_t;
+
+/* WIP - Move to next assignment 
+#define N_ARG_MAX    15     //MAX number of args for a command
+typedef struct command{
+    char exe [EXE_MAX];
+    char args[ARG_MAX];
+    int  argc;
+    char *argv[N_ARG_MAX + 1];  //last argv[LAST] must be \0
+}command_t;
+*/
+
+
+//Special character #defines
+#define SPACE_CHAR  ' '
+#define PIPE_CHAR   '|'
+#define PIPE_STRING "|"
+
+#define SH_PROMPT "dsh2> "
+#define EXIT_CMD "exit"
+
+//Standard Return Codes
+#define OK                       0
+#define WARN_NO_CMDS            -1
+#define ERR_TOO_MANY_COMMANDS   -2
+#define ERR_CMD_OR_ARGS_TOO_BIG -3
+#define ERR_CMD_ARGS_BAD        -4      //for extra credit
+#define ERR_MEMORY              -5
+#define ERR_EXEC_CMD            -6
+#define OK_EXIT                 -7
+
+//prototypes
+int alloc_cmd_buff(cmd_buff_t *cmd_buff);
+int free_cmd_buff(cmd_buff_t *cmd_buff);
+int clear_cmd_buff(cmd_buff_t *cmd_buff);
+int build_cmd_buff(char *cmd_line, cmd_buff_t *cmd_buff);
+
+//built in command stuff
+typedef enum {
+    BI_CMD_EXIT,
+    BI_CMD_DRAGON,
+    BI_CMD_CD,
+    BI_NOT_BI,
+    BI_EXECUTED,
+    BI_RC,
+} Built_In_Cmds;
+Built_In_Cmds match_command(const char *input); 
+Built_In_Cmds exec_built_in_cmd(cmd_buff_t *cmd);
+
+//main execution context
+int exec_local_cmd_loop();
+int exec_cmd(cmd_buff_t *cmd);
+
+
+
+
+//output constants
+#define CMD_OK_HEADER       "PARSED COMMAND LINE - TOTAL COMMANDS %d\n"
+#define CMD_WARN_NO_CMD     "warning: no commands provided\n"
+#define CMD_ERR_PIPE_LIMIT  "error: piping limited to %d commands\n"
+
+#endif
\ No newline at end of file

4-Shell-Part2/makefile

+# Compiler settings
+CC = gcc
+CFLAGS = -Wall -Wextra -g
+
+# Target executable name
+TARGET = dsh
+
+# Find all source and header files
+SRCS = $(wildcard *.c)
+HDRS = $(wildcard *.h)
+
+# Default target
+all: $(TARGET)
+
+# Compile source to executable
+$(TARGET): $(SRCS) $(HDRS)
+	$(CC) $(CFLAGS) -o $(TARGET) $(SRCS)
+
+# Clean up build files
+clean:
+	rm -f $(TARGET)
+
+test:
+	bats $(wildcard ./bats/*.sh)
+
+valgrind:
+	echo "pwd\nexit" | valgrind --leak-check=full --show-leak-kinds=all --error-exitcode=1 ./$(TARGET) 
+	echo "pwd\nexit" | valgrind --tool=helgrind --error-exitcode=1 ./$(TARGET) 
+
+# Phony targets
+.PHONY: all clean test
\ No newline at end of file

4-Shell-Part2/shell_roadmap.md

+## Proposed Shell Roadmap
+
+Week 5:  Shell CLI Parser Due
+
+Week 6:  Execute Basic Commands
+
+Week 7:  Add support for pipes (extra-credit for file redirection)
+
+Week 8:  Basic socket assignment
+
+Week 9:  Remote Shell Extension
+
+Week 11: Add support for something like `nsenter` to enter a namespace
\ No newline at end of file