This is signals/signal_functions.h, an example to accompany the book, The Linux Programming Interface.
This file is not printed in the book; it is the header file for signal_functions.c (Listing 20-4, page 408).
The source code file is copyright 2022, Michael Kerrisk, and is licensed under the GNU Lesser General Public License, version 3.
In the listing below, the names of Linux system calls and C library functions are hyperlinked to manual pages from the Linux man-pages project, and the names of functions implemented in the book are hyperlinked to the implementations of those functions.
/* signal_functions.h Header file for signal_functions.c. */ #ifndef SIGNAL_FUNCTIONS_H #define SIGNAL_FUNCTIONS_H #include <signal.h> #include "tlpi_hdr.h" int printSigMask(FILE *of, const char *msg); int printPendingSigs(FILE *of, const char *msg); void printSigset(FILE *of, const char *ldr, const sigset_t *mask); #endif
Note that, in most cases, the programs rendered in these web pages are not free standing: you'll typically also need a few other source files (mostly in the lib/ subdirectory) as well. Generally, it's easier to just download the entire source tarball and build the programs with make(1). By hovering your mouse over the various hyperlinked include files and function calls above, you can see which other source files this file depends on.