corrected build instr + mmap check

diff --git a/efp_extract.c b/efp_extract.c
index 7198ef4bee4804dadabf938b87276aa7da0fd44e..bf660651453681de8c14ca16abe9b2213a97d4cb 100644 (file)
--- a/efp_extract.c
+++ b/efp_extract.c
@@ -3,7 +3,7 @@
  *
  * author: hackbard@hackdaworld.org
  *
- * build: gcc -Wall efp_extract -o efp_extract
+ * build: gcc -Wall efp_extract.c -o efp_extract
  * usage: ./efp_extract file.efp
  *        chmod 640 file_??
  *
@@ -99,6 +99,10 @@ int main(int argc,char **argv) {
 
        printf("mapping file into memory ...\n");
        map=mmap(0,offset[nof-1]+len[nof-1],PROT_READ,MAP_SHARED,fd,0);
+       if(map==MAP_FAILED) {
+               perror("mmap");
+               return -1;
+       }
 
        for(i=0;i<nof;i++) {