error_temp - identify soft syscall error codes #include <error.h> int error_temp(e); int e; error_temp returns 1 if syscall error code e is a soft error, 0 if it is a hard error. Normally e is errno . A hard error is persistent: file not found, read-only file system, symbolic link loop, etc. A soft error is usually transient: out of memory, out of disk space, I/O error, disk quota exceeded, connection refused, host unreachable, etc. error(3)