refactor: c/ -> usr/, compiled program blobs out of the source tree

Userland sources live in usr/ (fits the Unix theme better than 'c').
SDCC output .bin blobs land in build/usr/ with the other build artifacts
instead of littering the source dir; programs.asm INCBINs them from there.
Byte-identical ROM.

1 files changed, 17 insertions, 0 deletions

diff --git a/usr/cat.c b/usr/cat.c
new file mode 100644
index 0000000..790cb88
--- /dev/null
+++ b/usr/cat.c
@@ -0,0 +1,17 @@
+#include "gbos.h"
+/* cat [file]: print a file, or copy stdin to stdout until EOF. */
+void main(void) {
+    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 == EISDIR) { puts("cat: is a directory"); nl(); return; }
+        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); }
+    }
+}