HW1: RasShell 已實作基本的指令輸入功能

1 files changed, 223 insertions, 10 deletions

diff --git a/hw1/shell.c b/hw1/shell.c
index 0d6db2a..b4acf4c 100644
--- a/hw1/shell.c
+++ b/hw1/shell.c
@@ -8,6 +8,7 @@
 
 #include <ctype.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <inttypes.h>
 #include <locale.h>
 #include <pwd.h>
@@ -15,8 +16,11 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
+#include <sys/wait.h>
+#include <termios.h>
 #include <time.h>
 #include <unistd.h>
 
@@ -28,14 +32,6 @@
 #define STRV(x)                  ((char**)(x))
 #define STR(x)                   ((char*)(x))
 
-typedef int (*RasShellFunc) (char* argv[]);
-typedef char* (*RasShellReadline) (void* data);
-
-typedef struct {
-	char*        cmd;
-	RasShellFunc func;
-} RasShellBuiltin;
-
 typedef struct {
 	uint64_t count;
 	char*    reason;
@@ -52,6 +48,7 @@ typedef struct {
 
 typedef struct {
 	List*    argrp;             /* A List of RasShellCmdComp */
+	pid_t    pgid;              /* process group ID */
 } RasShellCmd;
 
 typedef struct {
@@ -60,15 +57,28 @@ typedef struct {
 	List*    saved_list;       /* A list of RasShellSaved */
 	char*    saved_tmpdir;
 	int      last_rval;
+	pid_t    pid;
+	pid_t    pgid;
 	int      attr_login  : 1;  /* login shell */
 	int      attr_rshell : 1;  /* restricted shell */
 	int      attr_debug  : 1;  /* debug message */
+	int      attr_isterm : 1;  /* shell is run in a terminal */
 	char*    user_name;
 	char     user_ps;
 	int      req_exit    : 1;  /* request for exit */
 	int      req_exit_status;  /* requested exit status */
+	int      term_fd;          /* shell terminal fd */
+	struct termios tmode;      /* shell terminal mode */
 } RasShell;
 
+typedef int (*RasShellFunc) (int argc, char* argv[], RasShell* shell);
+typedef char* (*RasShellRead) (void* data);
+
+typedef struct {
+	char*        cmd;
+	RasShellFunc func;
+} RasShellBuiltin;
+
 #define PARSE_QUOTE_REGULAR   '\"'
 #define PARSE_QUOTE_SUPER     '\''
 #define PARSE_ESCAPE          '\\'
@@ -135,7 +145,7 @@ static void complete_component (Array*** ws, int* append,
 }
 
 static int ras_shell_cmd_parse (
-	RasShellCmd* cmd, const char* cmdstr, RasShellReadline read_cb, void* data) {
+	RasShellCmd* cmd, const char* cmdstr, RasShellRead read_cb, void* data) {
 
 	bool is_quoted = false;
 	bool is_escaped = false;
@@ -144,6 +154,7 @@ static int ras_shell_cmd_parse (
 	int append = APPEND_STR; /* current working string */
 
 	cmd->argrp = list_create ();
+	cmd->pgid = 0;
 
 	RasShellCmdComp comp;
 	Array* str;
@@ -250,8 +261,195 @@ static void ras_shell_cmd_print (RasShellCmd* cmd) {
 	}
 }
 
+static int ras_shell_builtin_echo (int argc, char* argv[], RasShell* shell) {
+	for (int i = 1; argv[i] != NULL; i++) {
+		if (i > 1) {
+			putchar (' ');
+		}
+		fputs (argv[i], stdout);
+	}
+	putchar ('\n');
+	return 0;
+}
+
+static int ras_shell_builtin_exit (int argc, char* argv[], RasShell* shell) {
+	if (argc != 2) {
+		fprintf (
+			stderr, "%s: too %s arguments\n", argv[0], argc > 2 ? "many" : "few");
+		return 1;
+	}
+	shell->req_exit = true;
+	shell->req_exit_status = atoi (argv[1]);
+	return 0;
+}
+
+static int ras_shell_builtin_printenv (int argc, char* argv[], RasShell* shell) {
+	if (argc > 2) {
+		fprintf (stderr, "%s: too many arguments\n", argv[0]);
+		return 1;
+	}
+	if (argc < 2) {
+		extern char** environ;
+		for (int i = 0; environ[i] != NULL; i++) {
+			puts (environ[i]);
+		}
+	} else {
+		char* res = getenv (argv[1]);
+		if (res == NULL) {
+			return 1;
+		}
+		puts (res);
+	}
+	return 0;
+}
+
+static int ras_shell_builtin_setenv (int argc, char* argv[], RasShell* shell) {
+	if (argc != 3) {
+		fprintf (
+			stderr, "%s: too %s arguments\n", argv[0], argc > 3 ? "many" : "few");
+		return 1;
+	}
+	return - setenv (argv[1], argv[2], 1);
+}
+
 static int ras_shell_cmd_run (RasShellCmd* cmd, RasShell* shell) {
-	return -1;
+	const static RasShellBuiltin builtins[] = {
+		{ "echo",        ras_shell_builtin_echo         },
+		{ "exit",        ras_shell_builtin_exit         },
+		{ "printenv",    ras_shell_builtin_printenv     },
+		{ "setenv",      ras_shell_builtin_setenv       },
+		{  NULL,         NULL                           }
+	};
+
+	ListNode* iter = list_node_front (cmd->argrp);
+	pid_t child;
+	int pipefd[2], infile, outfile;
+
+	cmd->pgid = 0;
+	infile = STDIN_FILENO;
+	outfile = STDOUT_FILENO;
+
+	for (int i = 1; iter != NULL; iter = list_next (iter), i++) {
+		RasShellCmdComp* comp = list_data (iter);
+		RasShellFunc builtin_func = NULL;
+
+		for (int j = 0; builtins[j].cmd != NULL; j++) {
+			char* cmd = STRV (array_data (comp->arg))[0];
+			if (cmd == NULL) {
+				continue;
+			}
+			if (strcmp (builtins[j].cmd, cmd) == 0) {
+				builtin_func = builtins[j].func;
+				break;
+			}
+		}
+
+		if (list_len (cmd->argrp) <= 1 && builtin_func != NULL) {
+			return (*builtin_func)(
+				array_getlen (comp->arg) - 1,
+				STRV (array_data (comp->arg)), shell);
+		}
+
+		if (list_next (iter) != NULL) {
+			if (pipe (pipefd) < 0) {
+				fprintf (stderr, "%s: pipe: %s\n", shell->name, strerror (errno));
+				break;
+			}
+			outfile = pipefd[1];
+		} else {
+			if (array_getlen (comp->redir_stdout)) {
+				outfile = open (array_data (comp->redir_stdout), O_WRONLY | O_CREAT | O_TRUNC);
+				if (outfile < 0) {
+					fprintf (stderr, "%s: %s: %s\n",
+						shell->name, STR (array_data (comp->redir_stdout)), strerror (errno));
+					break;
+				}
+			} else {
+				outfile = STDOUT_FILENO;
+			}
+			if (array_getlen (comp->tapipe)) {
+				int tpnum;
+				sscanf (STR (array_data (comp->tapipe)) + 1, "%d", &tpnum);
+				if (tpnum < 1) {
+					fprintf (stderr, "%s: invalid TA pipe number `%s\'\n",
+						shell->name, STR (array_data (comp->tapipe)));
+					break;
+				}
+				// TODO: TA pipe handling
+			}
+		}
+
+		child = fork ();
+
+		if (child < 0) {
+			fprintf (stderr, "%s: fork: %s\n", shell->name, strerror (errno));
+			continue;
+		} else if (child > 0) {
+			/* parent */
+
+			if (cmd->pgid == 0) {
+				cmd->pgid = child;
+			}
+			setpgid (child, cmd->pgid);
+
+		} else {
+			/* child */
+
+			pid_t pid = getpid ();
+			if (cmd->pgid == 0) {
+				cmd->pgid = pid;
+			}
+			setpgid (pid, cmd->pgid);
+			if (shell->attr_isterm) {
+				tcsetpgrp (shell->attr_isterm, cmd->pgid);
+			}
+
+			if (infile != STDIN_FILENO) {
+				dup2 (infile, STDIN_FILENO);
+				close (infile);
+			}
+			if (outfile != STDOUT_FILENO) {
+				dup2 (outfile, STDOUT_FILENO);
+				close (STDOUT_FILENO);
+			}
+
+			if (builtin_func == NULL) {
+				char* execname = STRV (array_data (comp->arg))[0];
+				char** execargv = STRV (array_data (comp->arg));
+				execvp (execname, execargv);
+				fprintf (stderr, "%s: %s: %s\n", shell->name, execname, strerror (errno));
+				exit (1);
+			}
+		}
+
+		if (infile != STDIN_FILENO) {
+			close (infile);
+		}
+		if (outfile != STDOUT_FILENO) {
+			close (outfile);
+		}
+	}
+
+/*	if (shell->attr_isterm) {
+		tcsetpgrp (shell->term_fd, cmd->pgid);
+	}*/
+
+	int status = 0;
+	waitpid (- cmd->pgid, &status, 0);
+
+	if (shell->attr_isterm) {
+		tcsetpgrp (shell->term_fd, shell->pgid);
+		tcsetattr (shell->term_fd, TCSADRAIN, &shell->tmode);
+	}
+
+	if (infile != STDIN_FILENO) {
+		close (infile);
+	}
+	if (outfile != STDOUT_FILENO) {
+		close (outfile);
+	}
+
+	return WEXITSTATUS (status);
 }
 
 static void ras_shell_cmd_destroy (RasShellCmd* cmd) {
@@ -283,10 +481,14 @@ static char* ras_shell_cmd_read (void* data) {
 }
 
 static int ras_shell_init (RasShell* shell, int argc, char* argv[]) {
+
 	shell->last_rval = 0;
+	shell->pid = getpid ();
+	shell->pgid = getpgid (shell->pid);
 	shell->attr_login = argv[0][0] == '-';
 	shell->attr_rshell = false;
 	shell->attr_debug = false;
+	shell->attr_isterm = isatty (STDIN_FILENO) == 1;
 	shell->req_exit = false;
 	shell->req_exit_status = 0;
 
@@ -347,6 +549,17 @@ static int ras_shell_init (RasShell* shell, int argc, char* argv[]) {
 	shell->user_name = pwname == NULL ? NULL : xstrdup (pwname->pw_name);
 	shell->user_ps = geteuid () ? '$' : '#';
 
+	if (shell->attr_isterm) {
+		shell->term_fd = STDIN_FILENO;
+		if (tcgetattr (shell->term_fd, &shell->tmode) < 0) {
+			shell->attr_isterm = false;
+		}
+	}
+
+	if (shell->attr_rshell) {
+		setenv ("PATH", "bin:.", 1);
+	}
+
 	return 0;
 }