This is lib/get_num.h (Listing 3-5, page 59), 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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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.
/* get_num.h Header file for get_num.c. */ #ifndef GET_NUM_H #define GET_NUM_H #define GN_NONNEG 01 /* Value must be >= 0 */ #define GN_GT_0 02 /* Value must be > 0 */ /* By default, integers are decimal */ #define GN_ANY_BASE 0100 /* Can use any base - like strtol(3) */ #define GN_BASE_8 0200 /* Value is expressed in octal */ #define GN_BASE_16 0400 /* Value is expressed in hexadecimal */ long getLong(const char *arg, int flags, const char *name); int getInt(const char *arg, int flags, const char *name); #endif
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