1 files changed, 87 insertions, 0 deletions
diff --git a/xextest.c b/xextest.c
new file mode 100644
index 0000000..06614ab
--- /dev/null
+++ b/xextest.c
@@ -0,0 +1,87 @@
+#include <stdio.h>
+#include "xex.h"
+
+/* This is a minimal program illustrating the use of the xex library.
+
+	It expects to read one or more Atari executables from standard
+	input, and writes one (possibly multi-segment) Atari executable
+	to standard output.
+
+	This code is provided an an example only; for a useful real-world
+	tool, use xexcat.
+
+	To compile: "make xextest" if you have the full bw_atari8_utils
+	source distribution. Otherwise, (assuming you at least have xex.c
+	and xex.h): gcc -o xextest xextest.c xex.c (should work with other
+	compilers too).
+ */
+
+int main(int argc, char **argv) {
+	xex_segment seg;
+	unsigned char buffer[64 * 1024]; /* 64K buffer is guaranteed big enough */
+	int count = 1;
+
+	/* tell xex library to emit debugging trace to stderr. Default value
+		is 0 (no trace). */
+	xex_verbose = 1;
+
+	/* xex_fread_seg_header() returns false on error or at EOF. */
+	while(xex_fread_seg_header(&seg, stdin)) {
+		seg.object = buffer;
+
+		/* We're using a static buffer here. If we were using dynamically
+			allocated buffers, we'd say "seg.object = malloc(seg.len)" above,
+			and put a "free(seg.object)" somewhere after the xex_fwrite_seg().
+
+			Note that the xex lib NEVER calls malloc() or free() itself.
+
+			(Also, it never calls any of the standard I/O functions except
+			fread(), fwrite(), feof(), or ferror(); you have to fopen() and
+			fclose() in the calling code).
+		 */
+
+		/* xex library doesn't care if the first segment is missing the
+			required Atari $FFFF header, so we handle it ourselves. */
+		if(count == 1 && !seg.has_ff_header)
+			fprintf(stderr, "missing initial $FFFF header (bad XEX file?)\n");
+
+		/* Force the first segment to have a $FFFF header, and remove the
+		  	(optional) $FFFF header from subsequent segments. */
+		seg.has_ff_header = (count == 1);
+
+		/* Read the segment data. xex_fread_seg_data() returns false for
+			failure (with xex_errno set to indicate the reason). An EOF in the
+			middle of a segment is an error (means the file was truncated). */
+		if(!xex_fread_seg_data(&seg, stdin))
+			break;
+
+		/* xex_fwrite_seg() returns true for success, or false for failure
+			(with xex_errno set). Unless you've diddled with seg's fields,
+			xex_errno will always be XERR_SYSCALL when xex_fwrite_seg()
+			fails (and xex_perror() or xex_strerror() will call the real
+			strerror() to get the system's error message). */
+		if(!xex_fwrite_seg(&seg, stdout))
+			break;
+
+		/* If we weren't using xex_verbose mode, we might want to call
+			xex_print_seg_info() ourselves to print some info about the
+			segment, like so: */
+
+		/* xex_print_seg_info(&seg); */
+
+		fprintf(stderr, "segment #%d done\n\n", count);
+		count++;
+	}
+
+	/* If xex_fread_seg_header() returned false due to EOF, xex_errno will
+		be zero (aka XERR_NONE). Otherwise, xex_fread_seg_header() didn't like
+		the header, or else xex_fread_seg_data() returned false (probably
+		due to a premature EOF in the middle of the segment data), so we print
+		an error message about it. */
+	if(xex_errno)
+		xex_perror("error");
+
+	/* xex_errno will be 0 for error or non-zero otherwise, so it's suitable
+		for use as a standard UNIX exit status. */
+	return xex_errno;
+}