lib/flags.c

   1 /* flags.c */
   2
   3 #include "flags.h"
   4
   5 /*
   6  * setflags:
   7  *  Applies a "+x-y+zab" style string to the inflags value.
   8  *
   9  * The "flagmask" input restricts the flags that can be changed.
  10  * The "reject" input specifies whether to silently drop or actively reject if:
  11  *  REJECT_UNKNOWN:    An unknown flag was specified
  12  *  REJECT_DISALLOWED: An attempt was made to manipute a flag disallowed by flagmask
  13  */
  14
  15 int setflags(flag_t *inflags, flag_t flagmask, char *flagstr, const flag *flagslist, short reject) {
  16   int dir,i;
  17   flag_t newflags;
  18   char *ch;
  19
  20   /* Work with a temporary copy */
  21   newflags=*inflags;
  22
  23   /* Default is to add flags */
  24   dir=1;
  25
  26   for(ch=flagstr;*ch;ch++) {
  27     if (*ch=='+') {
  28       dir=1;
  29       continue;
  30     }
  31
  32     if (*ch=='-') {
  33       dir=0;
  34       continue;
  35     }
  36
  37     for(i=0;flagslist[i].flagchar!='\0';i++) {
  38       if (*ch==flagslist[i].flagchar) {
  39         /* Check that the change is allowed */
  40         if (flagmask & flagslist[i].flagbit) {
  41           if (dir==0) {
  42             newflags &= (~flagslist[i].flagbit);
  43           } else {
  44             newflags |= flagslist[i].flagbit;
  45           }
  46         } else {
  47           if (reject & REJECT_DISALLOWED) {
  48             return REJECT_DISALLOWED;
  49           }
  50         }
  51         /* We matched, stop looking */
  52         break;
  53       }
  54     }
  55
  56     if (flagslist[i].flagchar=='\0') {
  57       /* We didn't match anything */
  58       if (reject & REJECT_UNKNOWN) {
  59         return REJECT_UNKNOWN;
  60       }
  61     }
  62   }
  63
  64   /* We reached the end without bailing out; assign the flag changes */
  65   *inflags=newflags;
  66   return REJECT_NONE;
  67 }
  68
  69 /*
  70  * printflags:
  71  *  Prints out which flags are currently set in a flag block
  72  */
  73 char *printflags(flag_t inflags, const flag *flaglist) {
  74   static char buf[34];
  75   int i;
  76   char *ch=buf;
  77
  78   *ch++='+';
  79
  80   for (i=0;flaglist[i].flagchar!='\0' && i<32;i++) {
  81     if (inflags&flaglist[i].flagbit) {
  82       *ch++=flaglist[i].flagchar;
  83     }
  84   }
  85
  86   *ch='\0';
  87   return buf;
  88 }
  89
  90 /*
  91  * printflagsornone:
  92  *  Prints out which flags are currently set in a flag block, or return "none"
  93  */
  94 char *printflagsornone(flag_t inflags, const flag *flaglist) {
  95   static char buf[34];
  96   int i;
  97   char *ch=buf;
  98
  99   *ch++='+';
 100
 101   for (i=0;flaglist[i].flagchar!='\0' && i<32;i++) {
 102     if (inflags&flaglist[i].flagbit) {
 103       *ch++=flaglist[i].flagchar;
 104     }
 105   }
 106
 107   *ch='\0';
 108   if (ch==(buf+1)) /* No flags set */
 109     return "none";
 110
 111   return buf;
 112 }
 113 /* ugh */
 114
 115 char *printflags_noprefix(flag_t inflags, const flag *flaglist) {
 116   static char buf[34];
 117   int i;
 118   char *ch=buf;
 119
 120   for (i=0;flaglist[i].flagchar!='\0' && i<32;i++) {
 121     if (inflags&flaglist[i].flagbit) {
 122       *ch++=flaglist[i].flagchar;
 123     }
 124   }
 125
 126   *ch='\0';
 127   return buf;
 128 }
 129
 130
 131
 132 /*
 133  * printflagdiff:
 134  *  Prints the flag changes needed to change "oldflags" into "newflags"
 135  */
 136
 137 char *printflagdiff(flag_t oldflags, flag_t newflags, const flag *flaglist) {
 138   static char buf[40];
 139   int i;
 140   char *ch=buf;
 141   int chd=0;
 142
 143   /* Removes first */
 144
 145   for (i=0;flaglist[i].flagchar!='\0' && i<32;i++) {
 146     if ((oldflags & flaglist[i].flagbit) && !(newflags & flaglist[i].flagbit)) {
 147       if (chd==0) {
 148         chd=1;
 149         *ch++='-';
 150       }
 151       *ch++=flaglist[i].flagchar;
 152     }
 153   }
 154
 155   /* Now adds */
 156   chd=0;
 157
 158   for (i=0;flaglist[i].flagchar!='\0' && i<32;i++) {
 159     if (!(oldflags & flaglist[i].flagbit) && (newflags & flaglist[i].flagbit)) {
 160       if (chd==0) {
 161         chd=1;
 162         *ch++='+';
 163       }
 164       *ch++=flaglist[i].flagchar;
 165     }
 166   }
 167
 168   *ch='\0';
 169   return buf;
 170 }