1 files changed, 171 insertions, 0 deletions
diff --git a/src/user/app/shell.c b/src/user/app/shell.c
new file mode 100644
index 0000000..0a8c44f
--- /dev/null
+++ b/src/user/app/shell.c
@@ -0,0 +1,171 @@
+#include <user/app/shell.h>
+#include <user/lib/stdlib.h>
+#include <user/tests/main.h>
+#include <shared/syscalls.h>
+#include <stdbool.h>
+
+static char *split(char *base) {
+	while (*base) {
+		if (*base == ' ' || *base == '\t') {
+			*base++ = '\0';
+			return base;
+		}
+		base++;
+	}
+	return NULL;
+}
+
+static int readline(char *buf, size_t max) {
+	char c;
+	size_t pos = 0;
+	while (file_read(stdin, &c, 1)) {
+		switch (c) {
+			case '\b':
+			case 0x7f:
+				/* for some reason backspace outputs 0x7f (DEL) */
+				if (pos != 0) {
+					printf("\b \b");
+					pos--;
+				}
+				break;
+			case '\n':
+			case '\r':
+				printf("\n");
+				buf[pos++] = '\0';
+				return pos;
+			default:
+				if (pos < max) {
+					printf("%c", c);
+					buf[pos] = c;
+					pos++;
+				}
+		}
+	}
+	return -1; // error
+}
+
+static void cmd_cat_ls(const char *args, bool ls) {
+	libc_file *file;
+	static char buf[512];
+	int len; // first used for strlen(args), then length of buffer
+
+	if (!args) 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
+		char *p = buf;
+		while (*p) p++;
+		if (p[-1] != '/') {
+			p[0] = '/';
+			p[1] = '\0';
+			len++;
+		}
+	}
+
+	file = file_open(buf, 0);
+	if (!file) {
+		printf("couldn't open.\n");
+		return;
+	}
+
+	while (!file->eof) {
+		int len = file_read(file, buf, sizeof buf);
+		if (len <= 0) break;
+
+		if (ls) {
+			for (int i = 0; i < len; i++)
+				if (buf[i] == '\0') buf[i] = '\n';
+		}
+		file_write(stdout, buf, len);
+	}
+	file_close(file);
+}
+
+static void cmd_hexdump(const char *args) {
+	static uint8_t buf[512];
+	int fd, len;
+
+	fd = _syscall_open(args, strlen(args), 0);
+	if (fd < 0) {
+		printf("couldn't open.\n");
+		return;
+	}
+
+	len = _syscall_read(fd, buf, sizeof buf, 0);
+	for (int i = 0; i < len; i += 16) {
+		printf("%08x  ", i);
+
+		for (int j = i; j < i + 8 && j < len; j++)
+			printf("%02x ", buf[j]);
+		printf(" ");
+		for (int j = i + 8; j < i + 16 && j < len; j++)
+			printf("%02x ", buf[j]);
+		printf(" |");
+
+		for (int j = i; j < i + 16 && j < len; j++) {
+			char c = '.';
+			if (0x20 <= buf[j] && buf[j] < 0x7f) c = buf[j];
+			printf("%c", c);
+		}
+		printf("|\n");
+	}
+
+	_syscall_close(fd);
+}
+
+static void cmd_touch(const char *args) {
+	int fd = _syscall_open(args, strlen(args), OPEN_CREATE);
+	if (fd < 0) {
+		printf("couldn't create file.\n");
+		return;
+	}
+	_syscall_close(fd);
+}
+
+void shell_loop(void) {
+	static char cmd[256];
+	int level = 0;
+	char *args;
+
+	for (;;) {
+		printf("%x$ ", level);
+		readline(cmd, 256);
+		args = split(cmd);
+		if (!strcmp(cmd, "echo")) {
+			printf("%s\n", args);
+		} else if (!strcmp(cmd, "cat")) {
+			cmd_cat_ls(args, false);
+		} else if (!strcmp(cmd, "ls")) {
+			cmd_cat_ls(args, true);
+		} else if (!strcmp(cmd, "hexdump")) {
+			cmd_hexdump(args);
+		} else if (!strcmp(cmd, "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");
+			}
+		} else if (!strcmp(cmd, "touch")) {
+			cmd_touch(args);
+		} else if (!strcmp(cmd, "shadow")) {
+			_syscall_mount(-1, args, strlen(args));
+		} else if (!strcmp(cmd, "exit")) {
+			_syscall_exit(0);
+		} else if (!strcmp(cmd, "fork")) {
+			if (_syscall_fork(0, NULL))
+				_syscall_await();
+			else level++;
+		} else if (!strcmp(cmd, "run_tests")) {
+			test_all();
+		} else if (!strcmp(cmd, "stress")) {
+			stress_all();
+		} else {
+			printf("unknown command :(\n");
+		}
+	}
+}