1 /* Report a SIGPIPE signal and exit. 2 Copyright (C) 2008-2021 Free Software Foundation, Inc. 3 4 This program is free software: you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 3 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 17 /* Written by Bruno Haible <bruno@clisp.org>, 2008. */ 18 19 /* SIGPIPE is the signal sent to a process calling write() on a pipe with no 20 readers. Together with the signal, the write() call is terminated with 21 return value -1, errno = EPIPE. Note that SIGPIPE is a *synchronous* 22 signal: it occurs only during write(), without delay (unless blocked). 23 24 The default reaction on SIGPIPE, namely terminating the process without 25 an error message, is suitable for programs which only produce output to 26 standard output and don't have side effects. 27 28 When a program has side effects, other than writing to standard output, the 29 suitable behaviour is either 30 (a) to exit with an error message 31 or - in certain cases, for example when writing to subprocesses - 32 (b) to continue the operation without writing to the pipe/socket with 33 no readers. 34 35 This file provides support for (a). 36 For (b), the program needs to know which of the output file descriptors 37 has no readers. This is usually implemented by blocking the SIGPIPE signal 38 and handling an EPIPE error indicator in all affected library calls 39 (write(), send(), fwrite(), fflush(), fclose(), etc.). */ 40 41 #ifndef _SIGPIPE_DIE_H 42 #define _SIGPIPE_DIE_H 43 44 #ifdef __cplusplus 45 extern "C" { 46 #endif 47 48 49 /* Emit an error message indicating a SIGPIPE signal, and terminate the 50 process with an error code. */ 51 /*extern*/ _Noreturn void sigpipe_die (void); 52 53 /* Install a SIGPIPE handler that invokes PREPARE_DIE and then emits an 54 error message and exits. PREPARE_DIE may be NULL, meaning a no-op. */ 55 extern void install_sigpipe_die_handler (void (*prepare_die) (void)); 56 57 58 #ifdef __cplusplus 59 } 60 #endif 61 62 63 #endif /* _SIGPIPE_DIE_H */