diff options
| -rw-r--r-- | src/dd.c | 21 |
1 files changed, 16 insertions, 5 deletions
@@ -48,6 +48,10 @@ # define SIGINFO SIGUSR1 #endif +#ifndef S_TYPEISSHM +# define S_TYPEISSHM(Mode) 0 +#endif + #define ROUND_UP_OFFSET(X, M) ((M) - 1 - (((X) + (M) - 1) % (M))) #define PTR_ALIGN(Ptr, M) ((Ptr) \ + ROUND_UP_OFFSET ((char *)(Ptr) - (char *)0, (M))) @@ -1260,11 +1264,18 @@ main (int argc, char **argv) o = seek_bytes; } - /* Attempt to use ftruncate only if STDOUT refers to a regular file. - On Linux 2.4.0, ftruncate fails with for non-regular files. */ - if (fstat (STDOUT_FILENO, &stdout_stat) == 0 - && S_ISREG (stdout_stat.st_mode) - && ftruncate (STDOUT_FILENO, o) < 0) + if (fstat (STDOUT_FILENO, &stdout_stat) != 0) + error (1, errno, _("cannot fstat %s"), quote (output_file)); + + /* Complain only when ftruncate fails on a regular file, a + directory, or a shared memory object, as the 2000-08 + POSIX draft specifies ftruncate's behavior only for these + file types. For example, do not complain when Linux 2.4 + ftruncate fails on /dev/fd0. */ + if (ftruncate (STDOUT_FILENO, o) != 0 + && (S_ISREG (stdout_stat.st_mode) + || S_ISDIR (stdout_stat.st_mode) + || S_TYPEISSHM (stdout_stat.st_mode))) { char buf[LONGEST_HUMAN_READABLE + 1]; if (seek_record) |