Initial version

3 files changed, 95 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..481e027
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+revb
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..3d324fc
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,19 @@
+PREFIX ?= /usr/local
+BINDIR ?= /bin
+
+CFLAGS = -g
+
+all: revb
+
+clean:
+	rm -f revb
+
+revb: revb.c
+
+install:
+	install -m 755 revb -t "$(DESTDIR)$(PREFIX)$(BINDIR)"
+
+uninstall:
+	rm -f "$(DESTDIR)$(PREFIX)$(BINDIR)/revb"
+
+.PHONY: all clean install uninstall
diff --git a/revb.c b/revb.c
new file mode 100644
index 0000000..cb1752c
--- /dev/null
+++ b/revb.c
@@ -0,0 +1,75 @@
+#include <unistd.h>
+#include <fcntl.h>
+#include <err.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#define CHUNKSIZE 4096
+
+uint8_t *
+load(FILE *file, uint8_t *data, ssize_t *datalen)
+{
+	ssize_t cap, len;
+	ssize_t nread;
+	int ret;
+
+	len = *datalen;
+	cap = len + CHUNKSIZE;
+	data = realloc(data, cap);
+	if (!data) err(1, "realloc");
+
+	while (1) {
+		if (len + CHUNKSIZE > cap) {
+			cap *= 2;
+			data = realloc(data, cap);
+			if (!data) err(1, "realloc");
+		}
+
+		nread = fread(data + len, 1, CHUNKSIZE, file);
+		if (nread <= 0) break;
+
+		len += nread;
+	}
+
+	*datalen = len;
+
+	return data;
+}
+
+int
+main(int argc, const char **argv)
+{
+	uint8_t *data, tmp;
+	ssize_t a, b, len;
+	FILE *file;
+	int i;
+
+	len = 0;
+	data = NULL;
+	if (argc > 1) {
+		for (i = 1; i < argc; i++) {
+			file = fopen(argv[i], "r");
+			if (!file) err(1, "fopen");
+			data = load(file, data, &len);
+			fclose(file);
+		}
+	} else {
+		data = load(stdin, data, &len);
+	}
+	if (!len) return 0;
+
+	a = 0;
+	b = len - 1;
+	while (a < b) {
+		tmp = data[a];
+		data[a] = data[b];
+		data[b] = tmp;
+		a++; b--;
+	}
+
+	if (!fwrite(data, len, 1, stdout))
+		err(1, "fwrite");
+
+	free(data);
+}