cat implementation

libc/src/stdio/stdio.c

@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+#include <kernel/uapi/uapi_syscall.h>
+
+extern int32_t syscall2(uint32_t eax, uint32_t ebx, uint32_t ecx);
+
+int rename(const char* old, const char* new) {
+    return syscall2(SYS_RENAME, (uintptr_t) old, (uintptr_t) new);
+}

modules/src/cat.c

@@ -0,0 +1,42 @@
+#include <stdio.h>
+#include <stdbool.h>
+
+#define BUF_SIZE 512
+
+bool cat(const char* path) {
+    char buf[BUF_SIZE] = "";
+    FILE* f = fopen(path, "r");
+
+    if (!f) {
+        return false;
+    }
+
+    while (true) {
+        int read = fread(buf, 1, BUF_SIZE - 1, f);
+        buf[read] = '\0';
+
+        printf("%s", buf);
+
+        if (read < BUF_SIZE - 1) {
+            break;
+        }
+    }
+
+    return true;
+}
+
+int main(int argc, char* argv[]) {
+    if (argc < 2) {
+        printf("usage: %s FILE...\n", argv[0]);
+        return 1;
+    }
+
+    for (int i = 1; i < argc; i++) {
+        if (!cat(argv[i])) {
+            printf("%s: failed to open '%s'\n", argv[0], argv[i]);
+            return 2;
+        }
+    }
+
+    return 0;
+}