Add blind-tee

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 52 insertions, 0 deletions

diff --git a/src/blind-tee.c b/src/blind-tee.c
new file mode 100644
index 0000000..9699d8c
--- /dev/null
+++ b/src/blind-tee.c
@@ -0,0 +1,52 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+USAGE("[file ...]")
+
+#if !defined(PIPE_BUF)
+# define PIPE_BUF BUFSIZ
+#endif
+
+int
+main(int argc, char *argv[])
+{
+	char buf[PIPE_BUF];
+	int *fds = alloca(argc * sizeof(*fds));
+	size_t i, n = 0, done;
+	ssize_t r, w, *ps;
+
+	UNOFLAGS(0);
+
+	fds[n++] = STDOUT_FILENO;
+	while (argc--)
+		fds[n++] = eopen(*argv++, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+
+	ps = alloca(n * sizeof(*ps));
+
+	while (n) {
+		memset(ps, 0, n * sizeof(*ps));
+		r = read(STDIN_FILENO, buf, sizeof(buf));
+		if (r < 0)
+			eprintf("read <stdin>:");
+		if (!r)
+			break;
+		for (done = 0; done < n;) {
+			for (i = 0; i < n; i++) {
+				if (ps[i] == r)
+					continue;
+				w = write(fds[i], buf + ps[i], r - ps[i]);
+				if (w < 0) {
+					close(fds[i]);
+					n--;
+					memmove(fds + i, fds + i + 1, (n - i) * sizeof(*fds));
+					memmove(ps  + i, ps  + i + 1, (n - i) * sizeof(*ps));
+				}
+				ps[i] += w;
+				if (ps[i] == r)
+					done++;
+			}
+		}
+	}
+
+	return 0;
+}