diff options
Diffstat (limited to 'misc.c')
| -rw-r--r-- | misc.c | 47 |
1 files changed, 47 insertions, 0 deletions
@@ -823,3 +823,50 @@ get_path_max (void) return value; } #endif + + +/* This code is stolen from gnulib. + If/when we abandon the requirement to work with K&R compilers, we can + remove this (and perhaps other parts of GNU make!) and migrate to using + gnulib directly. + + This is called only through atexit(), which means die() has already been + invoked. So, call exit() here directly. Apparently that works...? +*/ + +/* Close standard output, exiting with status 'exit_failure' on failure. + If a program writes *anything* to stdout, that program should close + stdout and make sure that it succeeds before exiting. Otherwise, + suppose that you go to the extreme of checking the return status + of every function that does an explicit write to stdout. The last + printf can succeed in writing to the internal stream buffer, and yet + the fclose(stdout) could still fail (due e.g., to a disk full error) + when it tries to write out that buffered data. Thus, you would be + left with an incomplete output file and the offending program would + exit successfully. Even calling fflush is not always sufficient, + since some file systems (NFS and CODA) buffer written/flushed data + until an actual close call. + + Besides, it's wasteful to check the return value from every call + that writes to stdout -- just let the internal stream state record + the failure. That's what the ferror test is checking below. + + It's important to detect such failures and exit nonzero because many + tools (most notably `make' and other build-management systems) depend + on being able to detect failure in other tools via their exit status. */ + +void +close_stdout (void) +{ + int prev_fail = ferror (stdout); + int fclose_fail = fclose (stdout); + + if (prev_fail || fclose_fail) + { + if (fclose_fail) + error (NILF, _("write error: %s"), strerror (errno)); + else + error (NILF, _("write error")); + exit (EXIT_FAILURE); + } +} |