diff options
Diffstat (limited to 'libgfortran/io/unix.c')
| -rw-r--r-- | libgfortran/io/unix.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/libgfortran/io/unix.c b/libgfortran/io/unix.c index 1158458..b35182d 100644 --- a/libgfortran/io/unix.c +++ b/libgfortran/io/unix.c @@ -138,6 +138,8 @@ typedef struct int prot; int ndirty; /* Dirty bytes starting at dirty_offset */ + int special_file; /* =1 if the fd refers to a special file */ + unsigned unbuffered:1, mmaped:1; char small_buffer[BUFFER_SIZE]; @@ -509,13 +511,14 @@ fd_truncate (unix_stream * s) return FAILURE; /* non-seekable files, like terminals and fifo's fail the lseek. - the fd is a regular file at this point */ - + Using ftruncate on a seekable special file (like /dev/null) + is undefined, so we treat it as if the ftruncate failed. + */ #ifdef HAVE_FTRUNCATE - if (ftruncate (s->fd, s->logical_offset)) + if (s->special_file || ftruncate (s->fd, s->logical_offset)) #else #ifdef HAVE_CHSIZE - if (chsize (s->fd, s->logical_offset)) + if (s->special_file || chsize (s->fd, s->logical_offset)) #endif #endif { @@ -915,6 +918,7 @@ fd_to_stream (int fd, int prot, int avoid_mmap) fstat (fd, &statbuf); s->file_length = S_ISREG (statbuf.st_mode) ? statbuf.st_size : -1; + s->special_file = !S_ISREG (statbuf.st_mode); #if HAVE_MMAP if (avoid_mmap) |