addrom

commit be215e106234f8a2061cfedb8d4561c7281629fa
parent ed830780cc8dd15c040cb5a6dd8e3f9d08ec16b6
Author: Quentin Rameau <quinq@fifth.space>
Date:   Tue, 10 Nov 2015 02:23:03 +0100

Permit to write input file or create output file from scratch

Diffstat:
addrom.c
 | 
95
++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------
config.mk
 | 
2
+-

2 files changed, 66 insertions(+), 31 deletions(-)
diff --git a/addrom.c b/addrom.c
@@ -64,18 +64,35 @@ addrom(char *datfile, const Rom *rom)
 }
 
 static uint32_t
-setgamecount(uint64_t n)
+getbingamecount(uint64_t n)
 {
 	return (n << 32 << 6) / 0x88888888;
 }
 
 static void
+setgamecount(char *buf, const uint32_t hexcount)
+{
+	*(uint32_t *)(buf) = hexcount;
+}
+
+static void
 ereadinfile(char *datbuf, const ssize_t size, FILE *infile)
 {
 	if (fread(datbuf, 1, size, infile) != size)
 		die("Couldn't read %zu bytes of input file %s\n", size, in);
 }
 
+static void *
+ecalloc(const ssize_t size)
+{
+	char *buf;
+
+	if (!(buf = calloc(size, 1)))
+		die("Can't allocate enough memory for buffer\n");
+
+	return buf;
+}
+
 static void
 usage(void)
 {
@@ -130,56 +147,74 @@ main(int argc, char *argv[])
 		break;
 	} ARGEND
 
-	if (!in || !out || !rom.romname)
+	if (!(in || out) || !rom.romname)
 		usage();
 
-	if (access(out, F_OK) != -1)
+	if (out && access(out, F_OK) != -1)
 		die("Output file %s exists and will not be overwritten\n",
 		    out);
 
-	if ((infd = open(in, O_RDONLY)) == -1)
-		die("Can't open input file %s\n", in);
+	/* create and populate buffer */
+	if (in) { /* from existing file */
+		if ((infd = open(in, out ? O_RDONLY : O_RDWR)) == -1)
+			die("Can't open input file %s\n", in);
 
-	if (fstat(infd, &st) == -1 || !S_ISREG(st.st_mode))
-		die("File %s is not a regular file\n", in);
+		if (fstat(infd, &st) == -1 || !S_ISREG(st.st_mode))
+			die("Input file %s is not a regular file\n", in);
 
-	if ((infilesize = st.st_size) < HEADERSZ)
-		die("Corrupted input file %s\n", in);
+		if ((infilesize = st.st_size) < HEADERSZ)
+			die("Corrupted input file %s\n", in);
 
-	if (!(infile = fdopen(infd, "r")))
-		die("Can't open input file %s\n", in);
+		if (!(infile = fdopen(infd, out ? "r" : "r+")))
+			die("Can't open input file %s\n", in);
 
-	outbufsize = infilesize + ENTRYSZ;
+		outbufsize = infilesize + ENTRYSZ;
 
-	if (!(outbuf = calloc(outbufsize, 1)))
-		die("Can't allocate enough memory for reading input file\n");
+		outbuf = ecalloc(outbufsize);
 
-	if (place == 0 || place * ENTRYSZ + HEADERSZ > infilesize)
-		offset = infilesize;
-	else
-		offset = HEADERSZ + (place - 1) * ENTRYSZ;
+		if (place == 0 || place * ENTRYSZ + HEADERSZ > infilesize)
+			offset = infilesize;
+		else
+			offset = HEADERSZ + (place - 1) * ENTRYSZ;
 
-	ereadinfile(outbuf, offset, infile);
+		ereadinfile(outbuf, offset, infile);
 
-	*(uint32_t *)(outbuf + HEADERSZSZ) = setgamecount(
-	    (infilesize - HEADERSZ) / ENTRYSZ + 1);
+		setgamecount(outbuf + HEADERSZSZ,
+		    getbingamecount((infilesize - HEADERSZ) / ENTRYSZ + 1));
 
-	addrom(outbuf + offset, &rom);
+		addrom(outbuf + offset, &rom);
 
-	ereadinfile(outbuf + offset + ENTRYSZ, infilesize - offset, infile);
+		ereadinfile(outbuf + offset + ENTRYSZ, infilesize - offset,
+		    infile);
+	} else { /* from scratch, position is ignored */
+		outbufsize = HEADERSZ + ENTRYSZ;
 
-	if (fclose(infile) == EOF)
-		fprintf(stderr, "There was an error while closing input file "
-		    "%s\n", in);
+		outbuf = ecalloc(outbufsize);
+
+		*(uint32_t *)(outbuf) = HEADERSZ;
+
+		setgamecount(outbuf + HEADERSZSZ, getbingamecount(1));
+
+		offset = HEADERSZ;
 
-	if (!(outfile = fopen(out, "w")))
+		addrom(outbuf + offset, &rom);
+	}
+
+	/* write out buffer */
+	if (out && !(outfile = fopen(out, "w")))
 		die("Can't open output file %s\n", out);
+	else if (!out && fseeko(infile, 0, SEEK_SET) == -1)
+		die("Couldn't seek input file %s\n", in);
 
-	if (fwrite(outbuf, 1, outbufsize, outfile) !=
+	if (fwrite(outbuf, 1, outbufsize, out ? outfile : infile) !=
 	    outbufsize)
-		die("Couldn't write all data to output file %s\n", out);
+		die("Couldn't write all data to file %s\n", out ? out : in);
+
+	if (in && fclose(infile) == EOF)
+		fprintf(stderr, "There was an error while closing input file "
+		    "%s\n", in);
 
-	if (fclose(outfile) == EOF)
+	if (out && fclose(outfile) == EOF)
 		fprintf(stderr, "There was an error while closing output file "
 		    "%s\n", out);
 
diff --git a/config.mk b/config.mk
@@ -7,7 +7,7 @@ INCS = -I. -I/usr/include
 LIBS = -L/usr/lib
 
 # flags
-CPPFLAGS += -D_POSIX_SOURCE
+CPPFLAGS += -D_POSIX_SOURCE -D_XOPEN_SOURCE=600
 CFLAGS += -std=c99 -pedantic -Wall -Os -s ${INCS} ${CPPFLAGS}
 LDFLAGS += -s ${LIBS}