This is daemons/become_daemon.h (Listing 37-1, page 770), an example from the book, The Linux Programming Interface.
The source code file is copyright 2022, Michael Kerrisk, and is licensed under the GNU Lesser General Public License, version 3.
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/* become_daemon.h Header file for become_daemon.c. */ #ifndef BECOME_DAEMON_H /* Prevent double inclusion */ #define BECOME_DAEMON_H /* Bit-mask values for 'flags' argument of becomeDaemon() */ #define BD_NO_CHDIR 01 /* Don't chdir("/") */ #define BD_NO_CLOSE_FILES 02 /* Don't close all open files */ #define BD_NO_REOPEN_STD_FDS 04 /* Don't reopen stdin, stdout, and stderr to /dev/null */ #define BD_NO_UMASK0 010 /* Don't do a umask(0) */ #define BD_MAX_CLOSE 8192 /* Maximum file descriptors to close if sysconf(_SC_OPEN_MAX) is indeterminate */ int becomeDaemon(int flags); #endif
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