wmweather+/subst.c

   1 #include "config.h"
   2
   3 /*  Copyright (C) 2002  Brad Jorsch <anomie@users.sourceforge.net>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18 */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <ctype.h>
  24 #include <sys/types.h>
  25
  26 #include "die.h"
  27 #include "subst.h"
  28
  29 #define GROW(var, len){{ \
  30     void *c; \
  31     len<<=1; \
  32     if(len==0) len=1; \
  33     if((var=realloc(c=var, len))==NULL){ \
  34         out=c; \
  35         warn("realloc error"); \
  36         goto fail; \
  37     } \
  38 }}
  39
  40 #define COPY(c) { \
  41     if(k>=formatlen) GROW(format, formatlen); \
  42     format[k++]=c; \
  43 }
  44
  45 char *subst(const char *s, struct subst_val *substitutes){
  46     int i, j, k, n, m;
  47     char *out=NULL;
  48     size_t outlen=0;
  49     char *format=NULL;
  50     size_t formatlen=0;
  51     int flags;
  52     ssize_t str_start;
  53
  54     for(i=j=0; s[i]!='\0'; i++){
  55         if(s[i]!='%'){
  56             if(j>=outlen) GROW(out, outlen);
  57             out[j++]=s[i];
  58             continue;
  59         }
  60         if(s[i+1]=='%'){
  61             if(j>=outlen) GROW(out, outlen);
  62             out[j++]=s[i++];
  63             continue;
  64         }
  65
  66         n=i;
  67         k=0;
  68         COPY('%');
  69
  70         /* skip flags */
  71         flags=0;
  72         while(strchr("#0- +'!", s[++n])){
  73             if(s[n]=='!'){
  74                 flags|=1;
  75             } else {
  76                 COPY(s[n]);
  77             }
  78         }
  79
  80         /* min width? */
  81         if(isdigit(s[n]) && s[n]!='0'){
  82             COPY(s[n]);
  83             while(isdigit(s[++n])){ COPY(s[n]); }
  84         }
  85
  86         /* precision? */
  87         if(s[n]=='.'){
  88             COPY('.');
  89             while(isdigit(s[++n])){ COPY(s[n]); }
  90         }
  91
  92         str_start=0;
  93         if(s[n]=='>'){
  94             if(s[n+1]=='-'){
  95                 flags|=2;
  96                 n++;
  97             }
  98             while(isdigit(s[++n])){
  99                 str_start=str_start*10+s[n]-'0';
 100             }
 101             if(flags&2) str_start=-str_start;
 102         }
 103
 104         for(m=0; s[n]!=substitutes[m].id && substitutes[m].id!='\0'; m++);
 105         if(substitutes[m].id=='\0'){
 106             warn("Unknown substitition character '%c' (at %d)\n", s[n], i);
 107             goto fail;
 108         }
 109
 110         switch(substitutes[m].type){
 111           case HEX:
 112           case FLOAT_E:
 113           case FLOAT_F:
 114           case FLOAT_G:
 115           case FLOAT_A:
 116             if(flags&1){
 117                 COPY(toupper(substitutes[m].type));
 118                 break;
 119             }
 120             /* fall through*/
 121
 122           default:
 123             COPY(substitutes[m].type);
 124             break;
 125         }
 126         COPY('\0');
 127
 128 #define PRINT(var) { while((k=j+snprintf(out+j, outlen-j, format, var))>=outlen) GROW(out, outlen); j=k; }
 129         switch(substitutes[m].type){
 130           case INT:
 131             PRINT(*(signed int *)substitutes[m].val);
 132             break;
 133
 134           case UINT:
 135           case OCTAL:
 136           case HEX:
 137             PRINT(*(unsigned int *)substitutes[m].val);
 138             break;
 139
 140           case FLOAT_E:
 141           case FLOAT_F:
 142           case FLOAT_G:
 143           case FLOAT_A:
 144             PRINT(*(double *)substitutes[m].val);
 145             break;
 146
 147           case CHAR:
 148             PRINT(*(char *)substitutes[m].val);
 149             if(flags&1) out[j-1]=toupper(out[j-1]);
 150             break;
 151
 152           case STRING:
 153             {
 154                 char *s=*(char **)substitutes[m].val;
 155                 if(str_start<0){
 156                     str_start+=strlen(s);
 157                     if(str_start<0) str_start=0;
 158                 } else if(str_start>strlen(s)){
 159                     s="";
 160                     str_start=0;
 161                 }
 162                 s+=str_start;
 163                 i=j;
 164                 PRINT(s);
 165                 if(flags&1){
 166                     for(; i<j; i++) out[i]=toupper(out[i]);
 167                 }
 168             }
 169             break;
 170
 171           default:
 172             warn("Unknown substitution type '%c'\n", substitutes[m].type);
 173             goto fail;
 174         }
 175
 176         i=n;
 177     }
 178
 179     free(format);
 180     if(j>=outlen) GROW(out, outlen);
 181     out[j]='\0';
 182     return out;
 183
 184 fail:
 185     free(format);
 186     free(out);
 187     return NULL;
 188 }