yeah i found that in the source
static void make_outfilename(char *infilename,char *outfilename)
/* creates an output file name for shifted data, used in fix mode */
{
char *basename;
if ((basename = strrchr(infilename,'/')))
basename++;
else
basename = infilename;
if (1 == output_dir_flag)
my_snprintf(outfilename,FILENAME_SIZE,"%s/%s",output_directory,basename);
else
my_snprintf(outfilename,FILENAME_SIZE,"%s",basename);
if (filename_contains_a_dot(outfilename))
*(strrchr(outfilename,'.')) = '\0';
strcat(outfilename,"-");
strcat(outfilename,POSTFIX_FIXED);
strcat(outfilename,".");
strcat(outfilename,op->extension);
}
It looks for a forward slash and gets the filename from there, then tacks that on to the output dir. if it finds no forward slash, it puts the whole path on
not an issue on mac/unix machines since the path separator there IS the forward slash