usr/src/lib/libast/common/path/pathfind.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  * Glenn Fowler
  25  * AT&T Research
  26  *
  27  * include style search support
  28  */
  29
  30 #include <ast.h>
  31 #include <error.h>
  32 #include <ls.h>
  33
  34 #define directory(p,s)  (stat((p),(s))>=0&&S_ISDIR((s)->st_mode))
  35 #define regular(p,s)    (stat((p),(s))>=0&&(S_ISREG((s)->st_mode)||streq(p,"/dev/null")))
  36
  37 typedef struct Dir_s                    /* directory list element       */
  38 {
  39         struct Dir_s*   next;           /* next in list                 */
  40         char            dir[1];         /* directory path               */
  41 } Dir_t;
  42
  43 static struct                           /* directory list state         */
  44 {
  45         Dir_t*          head;           /* directory list head          */
  46         Dir_t*          tail;           /* directory list tail          */
  47 } state;
  48
  49 /*
  50  * append dir to pathfind() include list
  51  */
  52
  53 int
  54 pathinclude(const char* dir)
  55 {
  56         register Dir_t* dp;
  57         struct stat     st;
  58
  59         if (dir && *dir && !streq(dir, ".") && directory(dir, &st))
  60         {
  61                 for (dp = state.head; dp; dp = dp->next)
  62                         if (streq(dir, dp->dir))
  63                                 return 0;
  64                 if (!(dp = oldof(0, Dir_t, 1, strlen(dir))))
  65                         return -1;
  66                 strcpy(dp->dir, dir);
  67                 dp->next = 0;
  68                 if (state.tail)
  69                         state.tail = state.tail->next = dp;
  70                 else
  71                         state.head = state.tail = dp;
  72         }
  73         return 0;
  74 }
  75
  76 /*
  77  * return path to name using pathinclude() list
  78  * path placed in <buf,size>
  79  * if lib!=0 then pathpath() attempted after include search
  80  * if type!=0 and name has no '.' then file.type also attempted
  81  * any *: prefix in lib is ignored (discipline library dictionary support)
  82  */
  83
  84 char*
  85 pathfind(const char* name, const char* lib, const char* type, char* buf, size_t size)
  86 {
  87         register Dir_t*         dp;
  88         register char*          s;
  89         char                    tmp[PATH_MAX];
  90         struct stat             st;
  91
  92         if (((s = strrchr(name, '/')) || (s = (char*)name)) && strchr(s, '.'))
  93                 type = 0;
  94
  95         /*
  96          * always check the unadorned path first
  97          * this handles . and absolute paths
  98          */
  99
 100         if (regular(name, &st))
 101         {
 102                 strncopy(buf, name, size);
 103                 return buf;
 104         }
 105         if (type)
 106         {
 107                 sfsprintf(buf, size, "%s.%s", name, type);
 108                 if (regular(buf, &st))
 109                         return buf;
 110         }
 111         if (*name == '/')
 112                 return 0;
 113
 114         /*
 115          * check the directory of the including file
 116          * on the assumption that error_info.file is properly stacked
 117          */
 118
 119         if (error_info.file && (s = strrchr(error_info.file, '/')))
 120         {
 121                 sfsprintf(buf, size, "%-.*s%s", s - error_info.file + 1, error_info.file, name);
 122                 if (regular(buf, &st))
 123                         return buf;
 124                 if (type)
 125                 {
 126                         sfsprintf(buf, size, "%-.*s%s%.s", s - error_info.file + 1, error_info.file, name, type);
 127                         if (regular(buf, &st))
 128                                 return buf;
 129                 }
 130         }
 131
 132         /*
 133          * check the include dir list
 134          */
 135
 136         for (dp = state.head; dp; dp = dp->next)
 137         {
 138                 sfsprintf(tmp, sizeof(tmp), "%s/%s", dp->dir, name);
 139                 if (pathpath(buf, tmp, "", PATH_REGULAR))
 140                         return buf;
 141                 if (type)
 142                 {
 143                         sfsprintf(tmp, sizeof(tmp), "%s/%s.%s", dp->dir, name, type);
 144                         if (pathpath(buf, tmp, "", PATH_REGULAR))
 145                                 return buf;
 146                 }
 147         }
 148
 149         /*
 150          * finally a lib related search on PATH
 151          */
 152
 153         if (lib)
 154         {
 155                 if (s = strrchr((char*)lib, ':'))
 156                         lib = (const char*)s + 1;
 157                 sfsprintf(tmp, sizeof(tmp), "lib/%s/%s", lib, name);
 158                 if (pathpath(buf, tmp, "", PATH_REGULAR))
 159                         return buf;
 160                 if (type)
 161                 {
 162                         sfsprintf(tmp, sizeof(tmp), "lib/%s/%s.%s", lib, name, type);
 163                         if (pathpath(buf, tmp, "", PATH_REGULAR))
 164                                 return buf;
 165                 }
 166         }
 167         return 0;
 168 }