ref: f4f19cdf1a8f0d2aa5f9fce10c896201528b5347
dir: /sys/src/cmd/upas/common/flags.c/
#include "common.h" static uchar flagtab[] = { 'a', Fanswered, 'D', Fdeleted, 'd', Fdraft, 'f', Fflagged, 'r', Frecent, 's', Fseen, 'S', Fstored, }; char* flagbuf(char *buf, int flags) { char *p, c; int i; p = buf; for(i = 0; i < nelem(flagtab); i += 2){ c = '-'; if(flags & flagtab[i+1]) c = flagtab[i]; *p++ = c; } *p = 0; return buf; } int buftoflags(char *p) { uchar flags; int i; flags = 0; for(i = 0; i < nelem(flagtab); i += 2) if(p[i>>1] == flagtab[i]) flags |= flagtab[i + 1]; return flags; } char* txflags(char *p, uchar *flags) { uchar neg, f, c, i; for(;;){ neg = 0; again: if((c = *p++) == '-'){ neg = 1; goto again; }else if(c == '+'){ neg = 0; goto again; } if(c == 0) return nil; for(i = 0;; i += 2){ if(i == nelem(flagtab)) return "bad flag"; if(c == flagtab[i]){ f = flagtab[i+1]; break; } } if(neg) *flags &= ~f; else *flags |= f; } }