Utilities for converting from and to binary

4 files changed, 136 insertions, 31 deletions

diff --git a/.gitignore b/.gitignore
index 94a873d..e385933 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,2 @@
-vgcore*
-bitcat
+bin
+unbin
diff --git a/Makefile b/Makefile
index 476bd96..a725a37 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,19 @@
-CFLAGS ?= 
-LDFLAGS ?= 
+DESTDIR ?=
+BINDIR ?= /usr/local/bin
 
-all: bitcat
+all: bin unbin
 
-%: %.c
-	$(CC) -o $@ $< $(CFLAGS) $(LDFLAGS)
+clean:
+	rm -f bin
 
+bin: bin.c
+
+unbin: unbin.c
+
+install: bin unbin
+	install -m755 $^ $(DESTDIR)$(BINDIR)
+
+uninstall:
+	rm -f $(DESTDIR)$(BINDIR)/{bin,unbin}
+
+.PHONY: all clean install uninstall
diff --git a/bin.c b/bin.c
new file mode 100644
index 0000000..ede1819
--- /dev/null
+++ b/bin.c
@@ -0,0 +1,88 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+
+#define ISFLAG(str, fshort, flong) (!strcmp(str, fshort) || !strcmp(str, flong))
+
+const char *usage = "USAGE: bin [-r] [-s SKIP] [-n COUNT] [FILE]\n";
+
+void
+die(const char *fmtstr, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmtstr);
+	vfprintf(stderr, fmtstr, ap);
+	va_end(ap);
+
+	exit(EXIT_FAILURE);
+}
+
+int
+main(int argc, const char **argv)
+{
+	unsigned char byte, bit;
+	size_t skip, cnt, pos;
+	const char *filepath;
+	int i, revbyte, cntset;
+	char *end;
+	FILE *f;
+
+	filepath = NULL;
+	cnt = skip = 0;
+	revbyte = 0;
+	cntset = 0;
+
+	for (i = 1; i < argc; i++) {
+		if (ISFLAG(argv[i], "-s", "--skip")) {
+			if (i++ >= argc - 1) goto missing_arg;
+			skip = strtoul(argv[i], &end, 0);
+			if (end && *end) goto bad_arg;
+		} else if (ISFLAG(argv[i], "-n", "--count")) {
+			if (i++ >= argc - 1) goto missing_arg;
+			cnt = strtoul(argv[i], &end, 0);
+			cntset = 1;
+			if (end && *end) goto bad_arg;
+		} else if (ISFLAG(argv[i], "-r", "--revb")) {
+			revbyte = 1;
+		} else if (ISFLAG(argv[i], "-h", "--help")) {
+			die(usage);
+		} else if (*argv[i] == '-') {
+			die("Unknown flag: %s\n", argv[i]);
+		} else if (filepath) {
+			die("Too many files specified\n");
+		} else {
+			filepath = argv[i];
+		}
+	}
+
+	if (!filepath)
+		f = stdin;
+	else if (!(f = fopen(filepath, "r")))
+		die("Failed to open file\n");
+
+	pos = 0;
+	while (!cntset || pos < skip + cnt) {
+		if (pos % 8 == 0) byte = fgetc(f);
+		if (feof(f)) break;
+		if (pos >= skip) {
+			if (revbyte)
+				bit = (byte >> (pos % 8)) & 1;
+			else
+				bit = (byte >> (7 - pos % 8)) & 1;
+			putchar(bit ? '1' : '0');
+		}
+		pos += 1;
+	}
+
+	fclose(f);
+
+	return EXIT_SUCCESS;
+
+missing_arg:
+	die("Flag %s expects an argument\n", argv[i]);
+
+bad_arg:
+	die("Argument has unexpected value: %s\n", argv[i]);
+}
diff --git a/bitcat.c b/unbin.c
index d27df14..e808076 100644
--- a/bitcat.c
+++ b/unbin.c
@@ -5,7 +5,7 @@
 
 #define ISFLAG(str, fshort, flong) (!strcmp(str, fshort) || !strcmp(str, flong))
 
-const char *usage = "USAGE: bitcat [-r] [-s SKIP] [-n COUNT] FILE\n";
+const char *usage = "USAGE: unbin [-r] [-s SKIP] [-n COUNT] [FILE]\n";
 
 void
 die(const char *fmtstr, ...)
@@ -23,24 +23,25 @@ int
 main(int argc, const char **argv)
 {
 	unsigned char byte, bit;
-	size_t skip, size, pos;
+	size_t skip, cnt, pos;
 	const char *filepath;
-	int i, revbyte;
+	int i, revbyte, cntset;
 	char *end;
 	FILE *f;
 
-	if (argc <= 1) die(usage);
-
 	filepath = NULL;
-	revbyte = size = skip = 0;
+	cnt = skip = 0;
+	revbyte = cntset = 0;
+
 	for (i = 1; i < argc; i++) {
 		if (ISFLAG(argv[i], "-s", "--skip")) {
 			if (i++ == argc - 1) goto missing_arg;
-			skip = strtol(argv[i], &end, 0);
+			skip = strtoul(argv[i], &end, 0);
 			if (end && *end) goto bad_arg;
 		} else if (ISFLAG(argv[i], "-n", "--count")) {
 			if (i++ == argc - 1) goto missing_arg;
-			size = strtol(argv[i], &end, 0);
+			cnt = strtoul(argv[i], &end, 0);
+			cntset = 1;
 			if (end && *end) goto bad_arg;
 		} else if (ISFLAG(argv[i], "-r", "--revb")) {
 			revbyte = 1;
@@ -56,25 +57,30 @@ main(int argc, const char **argv)
 	}
 
 	if (!filepath)
-		die("No file specified\n");
-
-	if (!(f = fopen(filepath, "r")))
+		f = stdin;
+	else if (!(f = fopen(filepath, "r")))
 		die("Failed to open file\n");
 
-	if (!size) {
-		fseek(f, 0, SEEK_END);
-		size = ftell(f) * 8;
-		fseek(f, 0, SEEK_SET);
-	}
-
-	for (pos = 0; pos < size + skip && !feof(f); pos++) {
-		if (pos % 8 == 0) byte = fgetc(f);
-		if (revbyte)
-			bit = (byte >> (7 - pos % 8)) & 1;
-		else
-			bit = (byte >> (pos % 8)) & 1;
-		if (pos >= skip) putchar(bit ? '1' : '0');
+	pos = 0;
+	while (!cntset || pos < cnt + skip) {
+		if (pos % 8 == 0) byte = 0;
+		bit = fgetc(f);
+		if (feof(f)) break;
+		if (bit != '1' && bit != '0')
+			continue;
+		bit = (bit == '1');
+		if (pos >= 0) {
+			if (revbyte)
+				byte |= bit << (pos % 8);
+			else
+				byte |= bit << (7 - pos % 8);
+			if (pos % 8 == 7)
+				putchar(byte);
+		}
+		pos += 1;
 	}
+	if (pos % 8 != 0)
+		putchar(byte);
 
 	fclose(f);