1 files changed, 86 insertions, 0 deletions
diff --git a/src/user/app/shell/builtins.c b/src/user/app/shell/builtins.c
new file mode 100644
index 0000000..fef46a5
--- /dev/null
+++ b/src/user/app/shell/builtins.c
@@ -0,0 +1,86 @@
+#include "builtins.h"
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+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);
+}
+
+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);
+}
+
+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);
+}