user/shell: use an array of function pointers for the builtins

3 files changed, 93 insertions, 66 deletions

diff --git a/src/user/app/shell/builtins.c b/src/user/app/shell/builtins.c
index 3a19a2f..e272cf3 100644
--- a/src/user/app/shell/builtins.c
+++ b/src/user/app/shell/builtins.c
@@ -4,54 +4,55 @@
 #include <string.h>
 #include <unistd.h>
 
-void cmd_cat_ls(const char *args, bool ls) {
+static void cmd_cat(int argc, const char **argv) {
+	// TODO loop over argv
+
 	FILE *file;
 	static char buf[512];
-	int len; // first used for strlen(args), then length of buffer
-
-	if (args) {
-		len = strlen(args);
-		memcpy(buf, args, len + 1); // no overflow check - the shell is just a PoC
 
-		if (ls) { // paths to directories always have a trailing slash
-			if (buf[len-1] != '/') {
-				buf[len] = '/';
-				buf[len+1] = '\0';
-			}
-		}
-
-		file = fopen(buf, "r");
-	} else if (ls) { /* ls default argument */
-		file = fopen("/", "r");
-	} else { /* cat default argument */
+	if (argv[1])
+		file = fopen(argv[1], "r");
+	else
 		file = file_clone(stdin);
-	}
 
 	if (!file) {
 		eprintf("couldn't open");
 		return;
 	}
 
-	while (!feof(file)) {
+	for (;;) {
 		int len = fread(buf, 1, sizeof buf, file);
 		if (len <= 0) break;
-
-		if (ls) {
-			for (int i = 0; i < len; i++)
-				if (buf[i] == '\0') buf[i] = '\n';
-		}
 		fwrite(buf, 1, len, stdout);
 	}
 	fclose(file);
 }
 
-void cmd_hexdump(const char *args) {
+static void cmd_echo(int argc, const char **argv) {
+	bool newline = true;
+	int i = 1;
+
+	if (!strcmp("-n", argv[i])) {
+		i++;
+		newline = false;
+	}
+
+	printf("%s", argv[i++]);
+	for (; argv[i]; i++)
+		printf(" %s", argv[i]);
+	if (newline)
+		printf("\n");
+}
+
+void cmd_hexdump(int argc, const char **argv) {
+	// TODO loop over argv
+	// TODO use fopen/fread
 	static uint8_t buf[512];
 	int fd, len;
 
-	fd = _syscall_open(args, strlen(args), 0);
+	fd = _syscall_open(argv[1], strlen(argv[1]), 0);
 	if (fd < 0) {
-		eprintf("couldn't open %s", args);
+		eprintf("couldn't open %s", argv[1]);
 		return;
 	}
 
@@ -77,11 +78,55 @@ void cmd_hexdump(const char *args) {
 	close(fd);
 }
 
-void cmd_touch(const char *args) {
-	int fd = _syscall_open(args, strlen(args), OPEN_CREATE);
+static void cmd_ls(int argc, const char **argv) {
+	// TODO loop over argv
+	FILE *file;
+	static char buf[512];
+
+	if (argv[1]) {
+		int len = strlen(argv[1]);
+		memcpy(buf, argv[1], len + 1); // TODO no overflow check
+
+		if (buf[len-1] != '/') {
+			buf[len] = '/';
+			buf[len+1] = '\0';
+		}
+
+		file = fopen(buf, "r");
+	} else {
+		file = fopen("/", "r");
+	}
+
+	if (!file) {
+		eprintf("couldn't open");
+		return;
+	}
+
+	for (;;) {
+		int len = fread(buf, 1, sizeof buf, file);
+		if (len <= 0) break;
+		for (int i = 0; i < len; i++)
+			if (buf[i] == '\0') buf[i] = '\n';
+		fwrite(buf, 1, len, stdout);
+	}
+	fclose(file);
+}
+
+static void cmd_touch(int argc, const char **argv) {
+	// TODO loop over argv
+	int fd = _syscall_open(argv[1], strlen(argv[1]), OPEN_CREATE);
 	if (fd < 0) {
-		eprintf("couldn't touch %s\n", args);
+		eprintf("couldn't touch %s\n", argv[1]);
 		return;
 	}
 	close(fd);
 }
+
+struct builtin builtins[] = {
+	{"cat", cmd_cat},
+	{"echo", cmd_echo},
+	{"hexdump", cmd_hexdump},
+	{"ls", cmd_ls},
+	{"touch", cmd_touch},
+	{NULL, NULL},
+};
diff --git a/src/user/app/shell/builtins.h b/src/user/app/shell/builtins.h
index bb52cef..aa2cd8c 100644
--- a/src/user/app/shell/builtins.h
+++ b/src/user/app/shell/builtins.h
@@ -2,6 +2,9 @@
 #include <camellia/syscalls.h>
 #include <stdbool.h>
 
-void cmd_cat_ls(const char *args, bool ls);
-void cmd_hexdump(const char *args);
-void cmd_touch(const char *args);
+struct builtin {
+	const char *name;
+	void (*fn)(int argc, const char **argv);
+};
+
+extern struct builtin builtins[];
diff --git a/src/user/app/shell/shell.c b/src/user/app/shell/shell.c
index 8bfe105..f47dc8d 100644
--- a/src/user/app/shell/shell.c
+++ b/src/user/app/shell/shell.c
@@ -36,8 +36,8 @@ static void run(char *cmd) {
 	char *argv[ARGV_MAX];
 	struct redir redir;
 
-	int ret = parse(cmd, argv, ARGV_MAX, &redir);
-	if (ret < 0) {
+	int argc = parse(cmd, argv, ARGV_MAX, &redir);
+	if (argc < 0) {
 		eprintf("error parsing command");
 		return;
 	}
@@ -63,39 +63,18 @@ static void run(char *cmd) {
 		exit(0);
 	}
 
-	if (!strcmp(argv[0], "echo")) {
-		printf("%s", argv[1]);
-		for (int i = 2; argv[i]; i++)
-			printf(" %s", argv[i]);
-		printf("\n");
-	} else if (!strcmp(argv[0], "fork")) {
-		main();
-	} else if (!strcmp(argv[0], "cat")) {
-		// TODO better argv handling
-		cmd_cat_ls(argv[1], false);
-	} else if (!strcmp(argv[0], "ls")) {
-		cmd_cat_ls(argv[1], true);
-	} else if (!strcmp(argv[0], "hexdump")) {
-		cmd_hexdump(argv[1]);
-	} else if (!strcmp(argv[0], "catall")) {
-		const char *files[] = {
-			"/init/fake.txt",
-			"/init/1.txt", "/init/2.txt",
-			"/init/dir/3.txt", NULL};
-		for (int i = 0; files[i]; i++) {
-			printf("%s:\n", files[i]);
-			cmd_cat_ls(files[i], false);
-			printf("\n");
+	for (struct builtin *iter = builtins; iter->name; iter++) {
+		if (!strcmp(argv[0], iter->name)) {
+			iter->fn(argc, argv);
+			exit(0);
 		}
-	} else if (!strcmp(argv[0], "touch")) {
-		cmd_touch(argv[1]);
+	}
+
+	execp(argv);
+	if (errno == EINVAL) {
+		eprintf("%s isn't a valid executable\n", argv[0]);
 	} else {
-		execp(argv);
-		if (errno == EINVAL) {
-			eprintf("%s isn't a valid executable\n", argv[0]);
-		} else {
-			eprintf("unknown command: %s\n", argv[0]);
-		}
+		eprintf("unknown command: %s\n", argv[0]);
 	}
 	exit(0); /* kills the subprocess */
 }