cond.y

   1 %{
   2
   3 #include <stdio.h>
   4 #include <string.h>
   5 #include <pcre.h>
   6
   7 #define OVECCOUNT 3
   8
   9 int yylex (void);
  10 void yyerror (char const *);
  11
  12 %}
  13
  14 %union {
  15         int b;
  16         int n;
  17         char* str;
  18 }
  19
  20 %token <str> CONST
  21 %token <str> REGEX
  22 %token <n> NUM
  23 %left EQ NEQ GE LE GT LT RE NRE
  24 %left '|' '&' '^'
  25 %left '!'
  26 %type <b> boo
  27
  28 %%
  29 input:  /* empty */
  30         | input line
  31 ;
  32
  33 line:   '\n'
  34         | boo '\n'              { printf("%s\n",$1?"true":"false"); }
  35         | error '\n'            { yyerrok; }
  36 ;
  37
  38 boo:     CONST EQ CONST         { $$ = ! strcmp($1, $3); }
  39         | CONST NEQ CONST       { $$ = !! strcmp($1, $3); }
  40         | CONST RE REGEX        {
  41                                         pcre *brum;
  42                                         int erroroffset;
  43                                         const char* error;
  44                                         int ovector[OVECCOUNT];
  45
  46                                         brum=pcre_compile($3,0,&error,&erroroffset,NULL);
  47                                         if (!brum){
  48                                                 puts("Mnau");
  49                                                 return 1;
  50                                         }
  51
  52                                         int res=pcre_exec(brum,NULL,$1,strlen($1),0,0,ovector,OVECCOUNT);
  53
  54                                         $$ = res >= 0;
  55                                         pcre_free(brum);
  56                                 }
  57         | CONST NRE REGEX       {
  58                                         pcre *brum;
  59                                         int erroroffset;
  60                                         const char* error;
  61                                         int ovector[OVECCOUNT];
  62
  63                                         brum=pcre_compile($3,0,&error,&erroroffset,NULL);
  64                                         if (!brum){
  65                                                 puts("Mnau");
  66                                                 return 1;
  67                                         }
  68
  69                                         int res=pcre_exec(brum,NULL,$1,strlen($1),0,0,ovector,OVECCOUNT);
  70
  71                                         $$ = res < 0;
  72                                         pcre_free(brum);
  73                                 }
  74         | NUM EQ NUM            { $$ = $1 == $3 }
  75         | NUM NEQ NUM           { $$ = $1 != $3 }
  76         | NUM GE NUM            { $$ = $1 >= $3 }
  77         | NUM LE NUM            { $$ = $1 <= $3 }
  78         | NUM GT NUM            { $$ = $1 > $3 }
  79         | NUM LT NUM            { $$ = $1 < $3 }
  80         | boo '|' boo           { $$ = $1 || $3 }
  81         | boo '&' boo           { $$ = $1 && $3 }
  82         | boo '^' boo           { $$ = ($1 || $3) && !($1 && $3) }
  83         | '!' boo               { $$ = ! $2 }
  84 ;
  85
  86 ;
  87 %%
  88
  89 #include <ctype.h>
  90 #include <stdlib.h>
  91
  92 #define BUFSIZE 4096
  93
  94 int
  95 yylex(void)
  96 {
  97
  98         int i, c, last;
  99
 100         while ((c = getchar ()) == ' ' || c == '\t');
 101
 102         if (c == '"'){
 103                 last = '"';
 104                 i = 0;
 105                 if (!(yylval.str = malloc(BUFSIZE))){
 106                         puts("Low memory");
 107                         exit(0);
 108                 }
 109                 while ((c = getchar()) != '"' || last == '\\'){
 110                         if (last=='\\' && c != '"')
 111                                 yylval.str[i-1] = c;
 112                         else {
 113                                 yylval.str[i] = c;
 114                                 i++;
 115                         }
 116                         last = c;
 117                         if (i >= BUFSIZE-1)
 118                                 break;
 119                 }
 120                 yylval.str[i] = '\0';
 121
 122                 return CONST;
 123         }
 124
 125         if (c == '\''){
 126                 last = '\'';
 127                 i = 0;
 128                 if (!(yylval.str = malloc(BUFSIZE))){
 129                         puts("Low memory");
 130                         exit(0);
 131                 }
 132                 while ((c = getchar()) != '\'' || last == '\\'){
 133                         if (last=='\\' && c != '\'')
 134                                 yylval.str[i-1] = c;
 135                         else {
 136                                 yylval.str[i] = c;
 137                                 i++;
 138                         }
 139                         last = c;
 140                         if (i >= BUFSIZE-1)
 141                                 break;
 142                 }
 143                 yylval.str[i] = '\0';
 144
 145                 return CONST;
 146         }
 147
 148         if (c == '/'){
 149                 last = '/';
 150                 i = 0;
 151                 if (!(yylval.str = malloc(BUFSIZE))){
 152                         puts("Low memory");
 153                         exit(0);
 154                 }
 155                 while ((c = getchar()) != '/' || last == '\\'){
 156                         if (last=='\\' && c != '/')
 157                                 yylval.str[i-1] = c;
 158                         else {
 159                                 yylval.str[i] = c;
 160                                 i++;
 161                         }
 162                         last = c;
 163                         if (i >= BUFSIZE-1)
 164                                 break;
 165                 }
 166                 yylval.str[i] = '\0';
 167
 168                 return REGEX;
 169         }
 170
 171         if (isdigit(c)){
 172                 ungetc(c,stdin);
 173                 scanf("%d",&yylval.n);
 174                 return NUM;
 175         }
 176
 177         if (c == '!'){
 178                 if ((c = getchar ()) == '=')
 179                         return NEQ;
 180                 else if (c == '~')
 181                         return NRE;
 182                 else
 183                         ungetc(c,stdin);
 184         }
 185
 186         if (c == '<'){
 187                 if ((c = getchar ()) == '=')
 188                         return LE;
 189                 else
 190                         return LT;
 191         }
 192
 193         if (c == '>'){
 194                 if ((c = getchar ()) == '=')
 195                         return GE;
 196                 else
 197                         return GT;
 198         }
 199
 200         if (c == '='){
 201                 if ((c = getchar ()) == '=')
 202                         return EQ;
 203                 else
 204                         ungetc(c,stdin);
 205         }
 206
 207         if (c == '~'){
 208                 if ((c = getchar ()) == '~')
 209                         return RE;
 210                 else
 211                         ungetc(c,stdin);
 212         }
 213
 214         if (c == EOF)
 215                 return 0;
 216
 217         return c;
 218 }
 219
 220 void
 221 yyerror (char const *s)
 222 {
 223         fprintf (stderr, "%s\n", s);
 224 }
 225
 226 int
 227 main(void)
 228 {
 229         return yyparse ();
 230 }