Add util.{c|h} to deduplicate code

8 files changed, 85 insertions, 75 deletions

diff --git a/ff2jpg.c b/ff2jpg.c
index 6f88a23..51f1fe6 100644
--- a/ff2jpg.c
+++ b/ff2jpg.c
@@ -11,8 +11,7 @@
 #include <jpeglib.h>
 
 #include "arg.h"
-
-char *argv0;
+#include "util.h"
 
 METHODDEF(void)
 jpeg_error(j_common_ptr js)
@@ -37,7 +36,7 @@ main(int argc, char *argv[])
 	struct jpeg_error_mgr jerr;
 	size_t rowlen;
 	uint64_t a;
-	uint32_t hdr[4], width, height, i, j, k, l;
+	uint32_t width, height, i, j, k, l;
 	uint16_t *row, mask[3] = { 0xffff, 0xffff, 0xffff };
 	uint8_t *rowout;
 	char *color, colfmt[] = "%#x%#x%#x";
@@ -75,19 +74,11 @@ main(int argc, char *argv[])
 		usage();
 	} ARGEND
 
-	if (argc)
+	if (argc) {
 		usage();
-
-	/* header */
-	if (fread(hdr, sizeof(*hdr), 4, stdin) != 4) {
-		goto readerr;
 	}
-	if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1)) {
-		fprintf(stderr, "%s: invalid magic value\n", argv0);
-		return 1;
-	}
-	width = ntohl(hdr[2]);
-	height = ntohl(hdr[3]);
+
+	read_ff_header(&width, &height);
 
 	if (width > SIZE_MAX / ((sizeof("RGBA") - 1) * sizeof(uint16_t))) {
 		fprintf(stderr, "%s: row length integer overflow\n", argv0);
diff --git a/ff2pam.c b/ff2pam.c
index 93bd26c..aca15cb 100644
--- a/ff2pam.c
+++ b/ff2pam.c
@@ -8,12 +8,12 @@
 #include <string.h>
 #include <unistd.h>
 
-static char *argv0;
+#include "util.h"
 
 int
 main(int argc, char *argv[])
 {
-	uint32_t hdr[4], width, height;
+	uint32_t width, height;
 	char buf[BUFSIZ];
 	size_t n, t;
 
@@ -24,19 +24,9 @@ main(int argc, char *argv[])
 		return 1;
 	}
 
-	/* header */
-	if (fread(hdr, sizeof(*hdr), 4, stdin) != 4) {
-		fprintf(stderr, "%s: file too short\n", argv0);
-		return 1;
-	}
-	if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1)) {
-		fprintf(stderr, "%s: invalid magic value\n", argv0);
-		return 1;
-	}
-	width = ntohl(hdr[2]);
-	height = ntohl(hdr[3]);
+	read_ff_header(&width, &height);
 
-	/* write header */
+	/* write PAM header */
 	printf("P7\n"
 	       "WIDTH %" PRIu32 "\n"
 	       "HEIGHT %" PRIu32 "\n"
diff --git a/ff2png.c b/ff2png.c
index 5731082..360ab00 100644
--- a/ff2png.c
+++ b/ff2png.c
@@ -9,11 +9,12 @@
 
 #include <png.h>
 
-static char *argv0;
+#include "util.h"
 
 void
 pngerr(png_structp pngs, const char *msg)
 {
+	(void)pngs;
 	fprintf(stderr, "%s: libpng: %s\n", argv0, msg);
 	exit(1);
 }
@@ -24,7 +25,7 @@ main(int argc, char *argv[])
 	png_structp pngs;
 	png_infop pngi;
 	size_t rowlen;
-	uint32_t hdr[4], width, height, i;
+	uint32_t width, height, i;
 	uint16_t *row;
 
 	argv0 = argv[0], argc--, argv++;
@@ -34,16 +35,7 @@ main(int argc, char *argv[])
 		return 1;
 	}
 
-	/* header */
-	if (fread(hdr, sizeof(*hdr), 4, stdin) != 4) {
-		goto readerr;
-	}
-	if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1)) {
-		fprintf(stderr, "%s: invalid magic value\n", argv0);
-		return 1;
-	}
-	width = ntohl(hdr[2]);
-	height = ntohl(hdr[3]);
+	read_ff_header(&width, &height);
 
 	/* load png */
 	pngs = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, pngerr,
diff --git a/ff2ppm.c b/ff2ppm.c
index 2a67eb2..f0f3956 100644
--- a/ff2ppm.c
+++ b/ff2ppm.c
@@ -9,8 +9,7 @@
 #include <string.h>
 
 #include "arg.h"
-
-char *argv0;
+#include "util.h"
 
 static void
 usage(void)
@@ -24,7 +23,7 @@ main(int argc, char *argv[])
 {
 	size_t rowlen;
 	uint64_t a;
-	uint32_t hdr[4], width, height, i, j, k, l;
+	uint32_t width, height, i, j, k, l;
 	uint16_t *row, mask[3] = { 0xffff, 0xffff, 0xffff };
 	uint8_t *rowout;
 	char *color, colfmt[] = "%#x%#x%#x";
@@ -58,16 +57,7 @@ main(int argc, char *argv[])
 	if (argc)
 		usage();
 
-	/* header */
-	if (fread(hdr, sizeof(*hdr), 4, stdin) != 4) {
-		goto readerr;
-	}
-	if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1)) {
-		fprintf(stderr, "%s: invalid magic value\n", argv0);
-		return 1;
-	}
-	width = ntohl(hdr[2]);
-	height = ntohl(hdr[3]);
+	read_ff_header(&width, &height);
 
 	if (width > SIZE_MAX / ((sizeof("RGBA") - 1) * sizeof(uint16_t))) {
 		fprintf(stderr, "%s: row length integer overflow\n", argv0);
diff --git a/jpg2ff.c b/jpg2ff.c
index 8ebc81d..85c935d 100644
--- a/jpg2ff.c
+++ b/jpg2ff.c
@@ -8,7 +8,7 @@
 
 #include <jpeglib.h>
 
-static char *argv0;
+#include "util.h"
 
 METHODDEF(void)
 jpeg_error(j_common_ptr js)
@@ -23,7 +23,7 @@ main(int argc, char *argv[])
 {
 	struct jpeg_decompress_struct js;
 	struct jpeg_error_mgr jerr;
-	uint32_t width, height, tmp32;
+	uint32_t width, height;
 	uint16_t *row;
 	size_t rowlen, i;
 	JSAMPARRAY jpgrow;
@@ -63,14 +63,8 @@ main(int argc, char *argv[])
 		return 1;
 	}
 
-	/* write header */
-	fputs("farbfeld", stdout);
-	tmp32 = htonl(width);
-	if (fwrite(&tmp32, sizeof(uint32_t), 1, stdout) != 1)
-		goto writerr;
-	tmp32 = htonl(height);
-	if (fwrite(&tmp32, sizeof(uint32_t), 1, stdout) != 1)
-		goto writerr;
+	/* write data */
+	write_ff_header(width, height);
 
 	while (js.output_scanline < js.output_height) {
 		/* jpeg_read_scanlines expects an array of pointers to
@@ -87,7 +81,6 @@ main(int argc, char *argv[])
 			row[4*i + 3] = htons(65535);
 		}
 
-		/* write data */
 		if (fwrite(row, sizeof(uint16_t), rowlen, stdout) != rowlen)
 			goto writerr;
 	}
diff --git a/png2ff.c b/png2ff.c
index 55456e3..515979d 100644
--- a/png2ff.c
+++ b/png2ff.c
@@ -8,7 +8,7 @@
 
 #include <png.h>
 
-static char *argv0;
+#include "util.h"
 
 void
 pngerr(png_structp pngs, const char *msg)
@@ -22,7 +22,7 @@ main(int argc, char *argv[])
 {
 	png_structp pngs;
 	png_infop pngi;
-	uint32_t width, height, rowlen, tmp32, r, i;
+	uint32_t width, height, rowlen, r, i;
 	uint16_t *row;
 	uint8_t **pngrows;
 
@@ -66,16 +66,9 @@ main(int argc, char *argv[])
 		return 1;
 	}
 
-	/* write header */
-	fputs("farbfeld", stdout);
-	tmp32 = htonl(width);
-	if (fwrite(&tmp32, sizeof(uint32_t), 1, stdout) != 1)
-		goto writerr;
-	tmp32 = htonl(height);
-	if (fwrite(&tmp32, sizeof(uint32_t), 1, stdout) != 1)
-		goto writerr;
-
 	/* write data */
+	write_ff_header(width, height);
+
 	switch(png_get_bit_depth(pngs, pngi)) {
 	case 8:
 		for (r = 0; r < height; ++r) {
diff --git a/util.c b/util.c
new file mode 100644
index 0000000..b374df9
--- /dev/null
+++ b/util.c
@@ -0,0 +1,51 @@
+/* See LICENSE file for copyright and license details. */
+#include <arpa/inet.h>
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "util.h"
+
+char *argv0;
+
+void
+read_ff_header(uint32_t *width, uint32_t *height)
+{
+	uint32_t hdr[4];
+
+	if (fread(hdr, sizeof(*hdr), LEN(hdr), stdin) != LEN(hdr)) {
+		fprintf(stderr, "%s: fread: %s", argv0, strerror(errno));
+		exit(1);
+	}
+
+	if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1)) {
+		fprintf(stderr, "%s: invalid magic value\n", argv0);
+		exit(1);
+	}
+
+	*width = ntohl(hdr[2]);
+	*height = ntohl(hdr[3]);
+}
+
+void
+write_ff_header(uint32_t width, uint32_t height)
+{
+	uint32_t tmp;
+
+	fputs("farbfeld", stdout);
+
+	tmp = htonl(width);
+	if (fwrite(&tmp, sizeof(tmp), 1, stdout) != 1) {
+		fprintf(stderr, "%s: write: %s", argv0, strerror(errno));
+		exit(1);
+	}
+
+	tmp = htonl(height);
+	if (fwrite(&tmp, sizeof(tmp), 1, stdout) != 1) {
+		fprintf(stderr, "%s: write: %s", argv0, strerror(errno));
+		exit(1);
+	}
+}
diff --git a/util.h b/util.h
new file mode 100644
index 0000000..02aee25
--- /dev/null
+++ b/util.h
@@ -0,0 +1,10 @@
+/* See LICENSE file for copyright and license details. */
+#include <stdint.h>
+#include <stdio.h>
+
+extern char *argv0;
+
+#define LEN(x) (sizeof (x) / sizeof *(x))
+
+void read_ff_header(uint32_t *width, uint32_t *height);
+void write_ff_header(uint32_t width, uint32_t height);