implement functions for pipeline_commands structure, update pipeline commands handler for handling array of commands, implement pipes handler for interprocess communication (as standard pipes in Linux shells)

Author: wiseStann

src/pipeline.c

@@ -3,54 +3,144 @@
 #include "../include/pipeline.h"
 #include "../include/sh_history.h"
 
+
+/*
+ *
+ */
+pipe_cmds_t*
+pipeline_commands_new()
+{
+    pipe_cmds_t* pcmds = (pipe_cmds_t*)sh_malloc(sizeof(pipe_cmds_t));
+    pcmds->cmds_list = (command_t**)sh_malloc(sizeof(command_t*));
+    pcmds->capacity = DEFAULT_PIPELINE_COMMANDS_CAP;
+    // for (int i = 0; i < pcmds->capacity; i++) {
+        // pcmds->cmds_list[i] = (command_t*)sh_malloc(sizeof(command_t));
+    // }
+    pcmds->size = 0;
+
+    return pcmds;
+}
+
+/*
+ *
+ */
+void
+pipeline_commands_push(pipe_cmds_t* commands, command_t* cmd)
+{
+    if (commands) {
+        if (commands->size >= commands->capacity)
+            pipeline_commands_reallocate(commands, commands->capacity * PIPELINE_COMMANDS_CAP_EXP_VAL);
+
+        commands->cmds_list[commands->size++] = cmd;
+    }
+}
+
+/*
+ *
+ */
+void
+pipeline_commands_reallocate(pipe_cmds_t* commands, unsigned bytes)
+{
+    commands->cmds_list = realloc((void*)commands->cmds_list, bytes);
+    commands->capacity = bytes;
+}
+
+/*
+ *
+ */
+void
+pipeline_commands_free(pipe_cmds_t* commands)
+{
+    if (commands) {
+        for (int i = 0; i < commands->size; i++) {
+            free(commands->cmds_list[i]);
+        }
+        free(commands->cmds_list);
+        free(commands);
+    }
+}
+
 /*
  *
  */
 int
-command_handle(command_t* command)
+pipeline_commands_handle(pipe_cmds_t* commands)
 {
-    COMMANDS_ALIASES cmd_alias = (COMMANDS_ALIASES)(command->table_index);
-    char** args = command_args_to_string_array(command);
-    int status;
+    if (commands->size == 1) {
+        command_t* whole_command = commands->cmds_list[0];
+        COMMANDS_ALIASES cmd_alias = (COMMANDS_ALIASES)(whole_command->table_index);
+        char** args = command_args_to_string_array(whole_command);
+        int status;
 
-    int ret;
-    if (fork() == 0) {
-        switch (cmd_alias) {
-            case CMDS_LIST_CMD:
-                commands_show();
-                break;
-            case CHANGE_PB_CMD:
-                if (command->args_num > 1)
-                    set_prompt_basename(command->arguments[1]->name);
-                else
-                    usage(command);
-                break;
-            case HIST_SHOW_CMD:
-                shell_history_show(history);
-                break;
-            case HIST_SAVE_CMD:
-                status = file_save_history(history);
-                if (status == STATUS_FAILURE)
-                    throw_error("! Unable to open the file to save history\n");
-                break;
-            case HIST_LOAD_CMD:
-                if (command->args_num == 2) {
-                    status = file_load_history(command->arguments[1]->name);
+        int ret;
+        if (fork() == 0) {
+            switch (cmd_alias) {
+                case CMDS_LIST_CMD:
+                    commands_show();
+                    break;
+                case CHANGE_PB_CMD:
+                    if (whole_command->args_num > 1)
+                        set_prompt_basename(whole_command->arguments[1]->name);
+                    else
+                        usage(whole_command);
+                    break;
+                case HIST_SHOW_CMD:
+                    shell_history_show(history);
+                    break;
+                case HIST_SAVE_CMD:
+                    status = file_save_history(history);
                     if (status == STATUS_FAILURE)
-                        throw_error("! Unable to open the file by a given id to load history\n");
-                } else
-                    usage(command);
-                break;
-            case HIST_FREE_CMD:
-                shell_history_free(history);
-                history = shell_history_new();
-                break;
-            default:
-                return execvp(command->name, args);
+                        throw_error("! Unable to open the file to save history\n");
+                    break;
+                case HIST_LOAD_CMD:
+                    if (whole_command->args_num == 2) {
+                        status = file_load_history(whole_command->arguments[1]->name);
+                        if (status == STATUS_FAILURE)
+                            throw_error("! Unable to open the file by a given id to load history\n");
+                    } else
+                        usage(whole_command);
+                    break;
+                case HIST_FREE_CMD:
+                    shell_history_free(history);
+                    history = shell_history_new();
+                    break;
+                default:
+                    return execvp(whole_command->name, args);
+            }
         }
+        wait(NULL);
+        string_array_free(args, whole_command->args_num);
     }
-    wait(NULL);
-    string_array_free(args, command->args_num);
+    else {
+        pipeline_pipes_handle(commands);
+    }
+
+    return STATUS_SUCCESS;
+}
 
-    return STATUS_SUCCESS; 
+/*
+ *
+ */
+int
+pipeline_pipes_handle(pipe_cmds_t* pipe_commands)
+{
+	int pipefd[2];
+    command_t* comm1 = pipe_commands->cmds_list[0];
+    char** args1 = command_args_to_string_array(comm1);
+    command_t* comm2 = pipe_commands->cmds_list[1];
+    char** args2 = command_args_to_string_array(comm2);
+    pipe(pipefd);
+    if (fork() == 0) {
+        //child
+        //write
+        close(pipefd[0]);
+        dup2(pipefd[1], STDOUT_FILENO);
+        execvp(comm1->name, args1);
+    } else {  
+        //parent
+        close(pipefd[1]);
+        dup2(pipefd[0], STDIN_FILENO);
+        execvp(comm2->name, args2);
+    }
+    return 0;
 }