BITSTRING(3) 1990 BITSTRING(3) NNAAMMEE bit_alloc, bit_clear, bit_decl, bit_ffs, bit_nclear, bit_nset, bit_set, bitstr_size, bit_test - bit-string mani- pulation macros SSYYNNOOPPSSIISS ##iinncclluuddee <<bbiittssttrriinngg..hh>> nnaammee == bbiitt__aalllloocc((nnbbiittss)) bbiittssttrr__tt **nnaammee;; iinntt nnbbiittss;; bbiitt__ddeeccll((nnaammee,, nnbbiittss)) bbiittssttrr__tt nnaammee;; iinntt nnbbiittss;; bbiitt__cclleeaarr((nnaammee,, bbiitt)) bbiittssttrr__tt nnaammee;; iinntt bbiitt;; bbiitt__ffffcc((nnaammee,, nnbbiittss,, vvaalluuee)) bbiittssttrr__tt nnaammee;; iinntt nnbbiittss,, **vvaalluuee;; bbiitt__ffffss((nnaammee,, nnbbiittss,, vvaalluuee)) bbiittssttrr__tt nnaammee;; iinntt nnbbiittss,, **vvaalluuee;; bbiitt__nncclleeaarr((nnaammee,, ssttaarrtt,, ssttoopp)) bbiittssttrr__tt nnaammee;; iinntt ssttaarrtt,, ssttoopp;; bbiitt__nnsseett((nnaammee,, ssttaarrtt,, ssttoopp)) bbiittssttrr__tt nnaammee;; iinntt ssttaarrtt,, ssttoopp;; bbiitt__sseett((nnaammee,, bbiitt)) bbiittssttrr__tt nnaammee;; iinntt bbiitt;; bbiittssttrr__ssiizzee((nnbbiittss)) iinntt nnbbiittss;; bbiitt__tteesstt((nnaammee,, bbiitt)) bbiittssttrr__tt nnaammee;; iinntt bbiitt;; DDEESSCCRRIIPPTTIIOONN These macros operate on strings of bits. _B_i_t__a_l_l_o_c returns a pointer of type _b_i_t_s_t_r__t * to sufficient space to store _n_b_i_t_s bits, or NULL if no space is available. Printed 7/27/90 June 1 BITSTRING(3) 1990 BITSTRING(3) _B_i_t__d_e_c_l is a macro for allocating sufficient space to store _n_b_i_t_s bits on the stack. _B_i_t_s_t_r__s_i_z_e returns the number of elements of type _b_i_t_s_t_r__t necessary to store _n_b_i_t_s bits. This is useful for copying bit strings. _B_i_t__c_l_e_a_r and _b_i_t__s_e_t clear or set the zero-based numbered bit _b_i_t, in the bit string _n_a_m_e. _B_i_t__n_s_e_t and _b_i_t__n_c_l_e_a_r set or clear the zero-based numbered bits from _s_t_a_r_t to _s_t_o_p in the bit string _n_a_m_e. _B_i_t__t_e_s_t evaluates to zero if the zero-based numbered bit _b_i_t of bit string _n_a_m_e is set, and non-zero otherwise. _B_i_t__f_f_s stores in the location referenced by _v_a_l_u_e the zero-based number of the first bit set in the array of _n_b_i_t_s bits referenced by _n_a_m_e. If no bits are set, the location referenced by _v_a_l_u_e is set to -1. _B_i_t__f_f_c stores in the location referenced by _v_a_l_u_e the zero-based number of the first bit not set in the array of _n_b_i_t_s bits referenced by _n_a_m_e. If all bits are set, the location referenced by _v_a_l_u_e is set to -1. The arguments to these macros are evaluated only once and may safely have side effects. EEXXAAMMPPLLEE #include <limits.h> #include <bitstring.h> #define LPR_BUSY_BIT 0 #define LPR_FORMAT_BIT 1 #define LPR_DOWNLOAD_BIT 2 #define LPR_AVAILABLE_BIT 9 #define LPR_MAX_BITS 10 make_lpr_available() { bitstr_t bit_decl(bitlist, LPR_MAX_BITS); ... bit_nclear(bitlist, 0, LPR_MAX_BITS - 1); ... if (!bit_test(bitlist, LPR_BUSY_BIT)) { bit_clear(bitlist, LPR_FORMAT_BIT); bit_clear(bitlist, LPR_DOWNLOAD_BIT); bit_set(bitlist, LPR_AVAILABLE_BIT); } } Printed 7/27/90 June 2 BITSTRING(3) 1990 BITSTRING(3) SSEEEE AALLSSOO malloc(3) Printed 7/27/90 June 3