user: break out the shell and tests into separate binaries

1 files changed, 213 insertions, 0 deletions

diff --git a/src/user/app/shell/shell.c b/src/user/app/shell/shell.c
new file mode 100644
index 0000000..9c51aeb
--- /dev/null
+++ b/src/user/app/shell/shell.c
@@ -0,0 +1,213 @@
+#include <camellia/syscalls.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static bool isspace(char c) {
+	return c == ' ' || c == '\t' || c == '\n';
+}
+
+static char *strsplit(char *base, char delim) {
+	if (!base) return NULL;
+	while (*base) {
+		if (delim ? *base == delim : isspace(*base)) {
+			*base++ = '\0';
+			return base;
+		}
+		base++;
+	}
+	return NULL;
+}
+
+static char *strtrim(char *s) {
+	char *end;
+	if (!s) return NULL;
+	while (isspace(*s)) s++;
+	end = s + strlen(s);
+	while (end > s && isspace(end[-1])) end--;
+	*end = '\0';
+	return s;
+}
+
+
+// TODO fgets
+static int readline(char *buf, size_t max) {
+	char c = '\0';
+	size_t pos = 0;
+	while (pos < (max-1) && c != '\n' && fread(&c, 1, 1, stdin))
+		buf[pos++] = c;
+	buf[pos++] = '\0';
+	return pos;
+}
+
+static void cmd_cat_ls(const char *args, bool ls) {
+	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 */
+		file = file_clone(stdin);
+	}
+
+	if (!file) {
+		printf("couldn't open.\n");
+		return;
+	}
+
+	while (!feof(file)) {
+		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);
+}
+
+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");
+	}
+
+	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;
+	}
+	close(fd);
+}
+
+int main(void) {
+	static char buf[256];
+	int level = 0;
+	char *cmd, *args, *redir;
+
+	for (;;) {
+		printf("%x$ ", level);
+
+		readline(buf, 256);
+		if (feof(stdin))
+			return 0;
+
+		cmd = strtrim(buf);
+		if (!*cmd) continue;
+
+		redir = strtrim(strsplit(cmd, '>'));
+		cmd = strtrim(cmd);
+		args = strtrim(strsplit(cmd, 0));
+
+		/* "special" commands that can't be handled in a subprocess */
+		if (!strcmp(cmd, "shadow")) {
+			_syscall_mount(-1, args, strlen(args));
+			continue;
+		} else if (!strcmp(cmd, "exit")) {
+			return 0;
+		} else if (!strcmp(cmd, "fork")) {
+			if (!fork()) level++;
+			else _syscall_await();
+			continue;
+		}
+
+		if (!fork()) {
+			if (redir && !freopen(redir, "w", stdout)) {
+				// TODO stderr
+				exit(0);
+			}
+
+			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 {
+				char *binname = cmd;
+				if (*cmd != '/') {
+					size_t cmdlen = strlen(cmd);
+					binname = malloc(cmdlen);
+					if (!binname) {
+						printf("sh: out of memory.\n");
+						exit(1);
+					}
+					memcpy(binname, "/bin/", 5);
+					memcpy(binname + 5, cmd, cmdlen + 1);
+				}
+
+				execv(binname, NULL);
+				if (errno == EINVAL) {
+					printf("%s isn't a valid executable\n", cmd);
+				} else {
+					printf("unknown command: %s\n", cmd);
+				}
+
+				if (binname != cmd)
+					free(binname);
+			}
+			exit(0);
+		} else {
+			_syscall_await();
+		}
+	}
+}