usr/src/lib/libast/common/comp/wordexp.c

   1 /***********************************************************************
   2 *                                                                      *
   3 *               This software is part of the ast package               *
   4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
   5 *                      and is licensed under the                       *
   6 *                  Common Public License, Version 1.0                  *
   7 *                    by AT&T Intellectual Property                     *
   8 *                                                                      *
   9 *                A copy of the License is available at                 *
  10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
  11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
  12 *                                                                      *
  13 *              Information and Software Systems Research               *
  14 *                            AT&T Research                             *
  15 *                           Florham Park NJ                            *
  16 *                                                                      *
  17 *                 Glenn Fowler <gsf@research.att.com>                  *
  18 *                  David Korn <dgk@research.att.com>                   *
  19 *                   Phong Vo <kpv@research.att.com>                    *
  20 *                                                                      *
  21 ***********************************************************************/
  22 #pragma prototyped
  23 /*
  24  * POSIX 1003.2 wordexp implementation
  25  */
  26
  27 #include        <ast.h>
  28 #include        <wordexp.h>
  29 #include        <stak.h>
  30
  31 struct list
  32 {
  33         struct list *next;
  34 };
  35
  36 /*
  37  * elimnates shell quoting as inserted with sh_fmtq
  38  * result relaces <string>
  39  * length of resulting string is returned.
  40  */
  41 static int      sh_unquote(char* string)
  42 {
  43         register char *sp=string, *dp;
  44         register int c;
  45         while((c= *sp) && c!='\'')
  46                 sp++;
  47         if(c==0)
  48                 return(sp-string);
  49         if((dp=sp) > string && sp[-1]=='$')
  50         {
  51                 register int n=stresc(sp+1);
  52                 /* copy all but trailing ' */
  53                 while(--n>0)
  54                         *dp++ = *++sp;
  55         }
  56         else
  57         {
  58                 while((c= *++sp) && c!='\'')
  59                         *dp++ = c;
  60         }
  61         *dp=0;
  62         return(dp-string);
  63 }
  64
  65 int     wordexp(const char *string, wordexp_t *wdarg, register int flags)
  66 {
  67         register Sfio_t *iop;
  68         register char *cp=(char*)string;
  69         register int c,quoted=0,literal=0,ac=0;
  70         int offset;
  71         char *savebase,**av;
  72         if(offset=staktell())
  73                 savebase = stakfreeze(0);
  74         if(flags&WRDE_REUSE)
  75                 wordfree(wdarg);
  76         else if(!(flags&WRDE_APPEND))
  77         {
  78                 wdarg->we_wordv = 0;
  79                 wdarg->we_wordc = 0;
  80         }
  81         if(flags&WRDE_UNDEF)
  82                 stakwrite("set -u\n",7);
  83         if(!(flags&WRDE_SHOWERR))
  84                 stakwrite("exec 2> /dev/null\n",18);
  85         stakwrite("print -f \"%q\\n\" ",16);
  86         if(*cp=='#')
  87                 stakputc('\\');
  88         while(c = *cp++)
  89         {
  90                 if(c=='\'' && !quoted)
  91                         literal = !literal;
  92                 else if(!literal)
  93                 {
  94                         if(c=='\\' && (!quoted || strchr("\\\"`\n$",c)))
  95                         {
  96                                 stakputc('\\');
  97                                 if(c= *cp)
  98                                         cp++;
  99                                 else
 100                                         c = '\\';
 101                         }
 102                         else if(c=='"')
 103                                 quoted = !quoted;
 104                         else if(c=='`' || (c=='$' && *cp=='('))
 105                         {
 106                                 if(flags&WRDE_NOCMD)
 107                                 {
 108                                         c=WRDE_CMDSUB;
 109                                         goto err;
 110                                 }
 111                                 /* only the shell can parse the rest */
 112                                 stakputs(cp-1);
 113                                 break;
 114                         }
 115                         else if(!quoted && strchr("|&\n;<>"+ac,c))
 116                         {
 117                                 c=WRDE_BADCHAR;
 118                                 goto err;
 119                         }
 120                         else if(c=='(') /* allow | and & inside pattern */
 121                                 ac=2;
 122                 }
 123                 stakputc(c);
 124         }
 125         stakputc(0);
 126         if(!(iop = sfpopen((Sfio_t*)0,stakptr(0),"r")))
 127         {
 128                 c = WRDE_NOSHELL;
 129                 goto err;
 130         }
 131         stakseek(0);
 132         ac = 0;
 133         while((c=sfgetc(iop)) != EOF)
 134         {
 135                 if(c=='\'')
 136                         quoted = ! quoted;
 137                 else if(!quoted && (c==' ' || c=='\n'))
 138                 {
 139                         ac++;
 140                         c = 0;
 141                 }
 142                 stakputc(c);
 143         }
 144         if(c=sfclose(iop))
 145         {
 146                 if(c==3 || !(flags&WRDE_UNDEF))
 147                         c=WRDE_SYNTAX;
 148                 else
 149                         c=WRDE_BADVAL;
 150                 goto err;
 151         }
 152         c = ac+2;
 153         if(flags&WRDE_DOOFFS)
 154                 c += wdarg->we_offs;
 155         if(flags&WRDE_APPEND)
 156                 av = reallocarray((void *)&wdarg->we_wordv[-1],
 157                     wdarg->we_wordc + c, sizeof (char *));
 158         else if(av = (char**)malloc(c*sizeof(char*)))
 159         {
 160                 if(flags&WRDE_DOOFFS)
 161                         memset(av,0,(wdarg->we_offs+1)*sizeof(char*));
 162                 else
 163                         av[0] = 0;
 164         }
 165         if(!av)
 166                 return(WRDE_NOSPACE);
 167         c = staktell();
 168         if(!(cp = (char*)malloc(sizeof(char*)+c)))
 169         {
 170                 c=WRDE_NOSPACE;
 171                 goto err;
 172         }
 173         ((struct list*)cp)->next = (struct list*)(*av);
 174         *av++ = (char*)cp;
 175         cp += sizeof(char*);
 176         wdarg->we_wordv = av;
 177         if(flags&WRDE_APPEND)
 178                 av += wdarg->we_wordc;
 179         wdarg->we_wordc += ac;
 180         if(flags&WRDE_DOOFFS)
 181                 av += wdarg->we_offs;
 182         memcpy((void*)cp,stakptr(offset),c);
 183         while(ac-- > 0)
 184         {
 185                 *av++ = cp;
 186                 sh_unquote(cp);
 187                 while(c= *cp++);
 188         }
 189         *av = 0;
 190         c=0;
 191 err:
 192         if(offset)
 193                 stakset(savebase,offset);
 194         else
 195                 stakseek(0);
 196         return(c);
 197 }
 198
 199 /*
 200  * free fields in <wdarg>
 201  */
 202 int wordfree(register wordexp_t *wdarg)
 203 {
 204         struct list *arg, *argnext;
 205         if(wdarg->we_wordv)
 206         {
 207                 argnext = (struct list*)wdarg->we_wordv[-1];
 208                 while(arg=argnext)
 209                 {
 210                         argnext = arg->next;
 211                         free((void*)arg);
 212                 }
 213                 free((void*)&wdarg->we_wordv[-1]);
 214                 wdarg->we_wordv = 0;
 215         }
 216         wdarg->we_wordc=0;
 217         return(0);
 218 }