byteswap things on the way in and out (sigh) of the file.

diff --git a/gpsbabel/mapsend.c b/gpsbabel/mapsend.c
index 6a913da2d5e94876df5ec9ad346108a9475e3333..17ec9817c50b00eed2712be60beb20550e0aaa0a 100644 (file)
--- a/gpsbabel/mapsend.c
+++ b/gpsbabel/mapsend.c
@@ -21,12 +21,32 @@
 #include <stdio.h>
 #include <string.h>
 
+
 #include "defs.h"
 #include "mapsend.h"
 
 static FILE *mapsend_file_in;
 static FILE *mapsend_file_out;
 
+static int endianness_tested;
+static int i_am_little_endian;
+
+static void
+test_endianness(void)
+{
+       union {
+                long l;
+                unsigned char uc[sizeof (long)];
+        } u;
+        unsigned int i;
+
+        u.l = 1;
+        i_am_little_endian = u.uc[0];
+
+       endianness_tested = 1;
+
+}
+
 static void
 mapsend_rd_init(const char *fname)
 {
@@ -43,6 +63,102 @@ mapsend_rd_deinit(void)
        fclose(mapsend_file_in);
 }
 
+static 
+size_t 
+my_fread8(void *ptr, FILE *stream)
+{
+       char cbuf[8];
+       char *cptr = ptr;
+
+       if (!endianness_tested) {
+               test_endianness();
+       }
+
+       if (i_am_little_endian) {       
+               fread(ptr, 8, 1, stream);
+       } else { 
+               fread(cbuf, 8, 1, stream);
+               cptr[0] = cbuf[7];
+               cptr[1] = cbuf[6];
+               cptr[2] = cbuf[5];
+               cptr[3] = cbuf[4];
+               cptr[4] = cbuf[3];
+               cptr[5] = cbuf[2];
+               cptr[6] = cbuf[1];
+               cptr[7] = cbuf[0];
+       }
+}
+
+static 
+size_t
+my_fwrite8(void *ptr, FILE *stream)
+{
+       char cbuf[8];
+       char *cptr = ptr;
+
+       if (!endianness_tested) {
+               test_endianness();
+       }
+
+       if (i_am_little_endian) {       
+               fwrite(ptr, 8, 1, stream);
+       } else {
+               cbuf[0] = cptr[7];
+               cbuf[1] = cptr[6];
+               cbuf[2] = cptr[5];
+               cbuf[3] = cptr[4];
+               cbuf[4] = cptr[3];
+               cbuf[5] = cptr[2];
+               cbuf[6] = cptr[1];
+               cbuf[7] = cptr[0];
+               fwrite(cbuf, 8, 1, stream);
+       }
+}
+
+static 
+size_t 
+my_fread4(void *ptr, FILE *stream)
+{
+       char cbuf[4];
+       char *cptr = ptr;
+       
+       if (!endianness_tested) {
+               test_endianness();
+       }
+
+       if (i_am_little_endian) {       
+               fread(ptr, 4, 1, stream);
+       } else {
+               fread(cbuf, 4, 1, stream);
+               cptr[0] = cbuf[3];
+               cptr[1] = cbuf[2];
+               cptr[2] = cbuf[1];
+               cptr[3] = cbuf[0];
+       }
+}
+
+static 
+size_t
+my_fwrite4(void *ptr, FILE *stream)
+{
+       char cbuf[4];
+       char *cptr = ptr;
+
+       if (!endianness_tested) {
+               test_endianness();
+       }
+
+       if (i_am_little_endian) {       
+               fwrite(ptr, 4, 1, stream);
+       } else {
+               cbuf[0] = cptr[3];
+               cbuf[1] = cptr[2];
+               cbuf[2] = cptr[1];
+               cbuf[3] = cptr[0];
+               fwrite(cbuf, 4, 1, stream);
+       }
+}
+
 static void
 mapsend_wr_init(const char *fname)
 {
@@ -84,7 +200,7 @@ mapsend_read(void)
 
        fread(&hdr, sizeof(hdr), 1, mapsend_file_in);
 
-       fread(&wpt_count, sizeof(wpt_count), 1, mapsend_file_in);
+       my_fread4(&wpt_count, mapsend_file_in);
 
        while (wpt_count--) {
                wpt_tmp = calloc(sizeof(*wpt_tmp), 1);
@@ -99,12 +215,12 @@ mapsend_read(void)
                p = strncpy(comment, tbuf, scount);
                p[scount] = '\0';
 
-               fread(&wpt_number, sizeof(wpt_number), 1, mapsend_file_in);
+               my_fread4(&wpt_number, mapsend_file_in);
                fread(&wpt_icon, sizeof(wpt_icon), 1, mapsend_file_in);
                fread(&wpt_status, sizeof(wpt_status), 1, mapsend_file_in);
-               fread(&wpt_alt, sizeof(wpt_alt), 1, mapsend_file_in);
-               fread(&wpt_long, sizeof(wpt_long), 1, mapsend_file_in);
-               fread(&wpt_lat, sizeof(wpt_lat), 1, mapsend_file_in);
+               my_fread8(&wpt_alt, mapsend_file_in);
+               my_fread8(&wpt_long, mapsend_file_in);
+               my_fread8(&wpt_lat, mapsend_file_in);
 
                wpt_tmp->shortname = strdup(name);
                wpt_tmp->description = strdup(comment);
@@ -120,34 +236,35 @@ static void
 mapsend_waypt_pr(waypoint *waypointp)
 {
        int n;
+       unsigned char c;
        double falt;
        double flong;
        double flat;
 static int cnt = 0;
 
-       n = strlen(waypointp->shortname);
-       fwrite(&n, 1, 1, mapsend_file_out);
-       fwrite(waypointp->shortname, n, 1, mapsend_file_out);
+       c = strlen(waypointp->shortname);
+       fwrite(&c, 1, 1, mapsend_file_out);
+       fwrite(waypointp->shortname, c, 1, mapsend_file_out);
 
-       n = strlen(waypointp->description);
-       fwrite(&n, 1, 1, mapsend_file_out);
-       fwrite(waypointp->description, n, 1, mapsend_file_out);
+       c = strlen(waypointp->description);
+       fwrite(&c, 1, 1, mapsend_file_out);
+       fwrite(waypointp->description, c, 1, mapsend_file_out);
 
        /* #, icon, status */
 n = ++cnt;
-       fwrite(&n, 4, 1, mapsend_file_out);
+       my_fwrite4(&n, mapsend_file_out);
 n = 0;
        fwrite(&n, 1, 1, mapsend_file_out);
 n = 1;
        fwrite(&n, 1, 1, mapsend_file_out);
 
        falt = waypointp->position.altitude.altitude_meters;
-       fwrite(&falt, sizeof(double), 1, mapsend_file_out);
+       my_fwrite8(&falt, mapsend_file_out);
 
        flong = waypointp->position.longitude.degrees;
-       fwrite(&flong, sizeof(double), 1, mapsend_file_out);
+       my_fwrite8(&flong, mapsend_file_out);
        flat = -waypointp->position.latitude.degrees;
-       fwrite(&flat, sizeof(double), 1, mapsend_file_out);
+       my_fwrite8(&flat, mapsend_file_out);
 }
 
 void
@@ -158,11 +275,11 @@ mapsend_write(void)
 int n = 0;
 
        fwrite(&hdr, sizeof(hdr), 1, mapsend_file_out);
-       fwrite(&wpt_count, sizeof(wpt_count), 1, mapsend_file_out);
+       my_fwrite4(&wpt_count, mapsend_file_out);
 
        waypt_disp_all(mapsend_waypt_pr);
 
-       fwrite(&n, 4, 1, mapsend_file_out);
+       my_fwrite4(&n, mapsend_file_out);
 /* TODO: Impelment routes here */
 }