feat: serial device interfacing

[lunaix-os.git] / lunaix-os / usr / cat / main.c

diff --git a/lunaix-os/usr/cat/main.c b/lunaix-os/usr/cat/main.c
new file mode 100644 (file)
index 0000000..0a15f8c
--- /dev/null
+++ b/lunaix-os/usr/cat/main.c
@@ -0,0 +1,31 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#define BUFSIZE 4096
+
+static char buffer[BUFSIZE];
+
+int
+main(int argc, const char* argv[])
+{
+    int fd = 0;
+    unsigned int size = 0;
+    for (int i = 1; i < argc; i++) {
+        fd = open(argv[i], FO_RDONLY);
+        if (fd < 0) {
+            printf("open failed: %s (error: %d)", argv[i], fd);
+            continue;
+        }
+
+        do {
+            size = read(fd, buffer, BUFSIZE);
+            write(stdout, buffer, size);
+        } while (size == BUFSIZE);
+
+        close(fd);
+    }
+
+    return 0;
+}
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