fix non persistent changes to file

when using MAP_PRIVATE with mmap(), the content is not updated in the
filesystem. Only the mapping is changed.

fixed by replacing MAP_PRIVATE by MAP_SHARED

Signed-off-by: Olivier Gayot <duskcoder@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/stegmp.c b/stegmp.c
index 6584e81..09d9e00 100644
--- a/stegmp.c
+++ b/stegmp.c
@@ -152,7 +152,7 @@ static int stegmp(const char *bmp_file, FILE *input)
 
     fstat(fileno(fh), &stat);
     addr = mmap(NULL, stat.st_size, PROT_READ | ((input) ? PROT_WRITE : 0),
-            MAP_PRIVATE, fileno(fh), 0);
+            MAP_SHARED, fileno(fh), 0);
 
     if (addr == MAP_FAILED) {
         fprintf(stderr, "%s: %m\n", bmp_file);