1 files changed, 12 insertions, 6 deletions
diff --git a/c/cat.c b/c/cat.c
index 4092778..dde58cd 100644
--- a/c/cat.c
+++ b/c/cat.c
@@ -1,10 +1,16 @@
 #include "gbos.h"
-/* cat: copy stdin to stdout until EOF (Ctrl-D / pipe end). */
+/* cat [file]: print a file, or copy stdin to stdout until EOF. */
 void main(void) {
-    char c;
-    for (;;) {
-        c = readc();
-        if (c == EOF) break;
-        putc(c);
+    char *argv[4];
+    unsigned char argc = argv_parse(argv, 4);
+    if (argc > 0) {
+        unsigned char fd = open(argv[0], O_READ);
+        int ch;
+        if (fd == NOFD) { puts("cat: no such file"); nl(); return; }
+        while ((ch = fgetc(fd)) >= 0) putc((char)ch);
+        close(fd);
+    } else {
+        char c;
+        for (;;) { c = readc(); if (c == EOF) break; putc(c); }
     }
 }