summaryrefslogtreecommitdiff
path: root/Build/source/texk/kpathsea/tilde.c
blob: 12e71434fd540349aaffa4e763ee75de834c9bd9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
/* tilde.c: expand user's home directories.

    Copyright 1997, 1998, 2005, Olaf Weber.
    Copyright 1993, 1995, 1996, 1997, 2008 Karl Berry.

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this library; if not, see <http://www.gnu.org/licenses/>.  */

#include <kpathsea/config.h>

#include <kpathsea/c-pathch.h>
#include <kpathsea/tilde.h>

#ifdef HAVE_PWD_H
#include <pwd.h>
#endif

#ifdef WIN32
#define HOMEVAR "USERPROFILE"
#else
#define HOMEVAR "HOME"
#endif

/* If NAME has a leading ~ or ~user, Unix-style, expand it to the user's
   home directory, and return a new malloced string.  If no ~, or no
   <pwd.h>, just return NAME.  */

string
kpathsea_tilde_expand (kpathsea kpse, const_string name)
{
  const_string expansion;
  const_string home;
  const_string prefix;
  
  (void)kpse; /* currenty not used */
  assert (name);

  /* If there is a leading "!!", set prefix to "!!", otherwise use
     the empty string.  After this, we can test whether a prefix was
     found by checking *prefix, and it is safe to unconditionally
     prepend it. */
  if (name[0] == '!' && name[1] == '!') {
    name += 2;
    prefix = "!!";
  } else {
    prefix = "";
  }
  
  /* If no leading tilde, do nothing, and return the original string.  */
  if (*name != '~') {
    if (*prefix)
      name -= 2;
    expansion = name;
  
  /* If a bare tilde, return the home directory or `.'.  (Very unlikely
     that the directory name will do anyone any good, but ...  */
  } else if (name[1] == 0) {
    home = getenv (HOMEVAR);
    if (!home) {
      home = ".";
    }
    expansion = concat (prefix, home);
  
  /* If `~/', remove any trailing / or replace leading // in $HOME.
     Should really check for doubled intermediate slashes, too.  */
  } else if (IS_DIR_SEP (name[1])) {
    unsigned c = 1;
    home = getenv (HOMEVAR);
    if (!home) {
      home = ".";
    }
    if (IS_DIR_SEP (*home) && IS_DIR_SEP (home[1])) {  /* handle leading // */
      home++;
    }
    if (IS_DIR_SEP (home[strlen (home) - 1])) {        /* omit / after ~ */
      c++;
    }
    expansion = concat3 (prefix, home, name + c);
  
  /* If `~user' or `~user/', look up user in the passwd database (but
     OS/2 doesn't have this concept.  */
  } else {
#ifdef HAVE_PWD_H
      struct passwd *p;
      string user;
      unsigned c = 2;
      while (!IS_DIR_SEP (name[c]) && name[c] != 0) /* find user name */
        c++;
      
      user = (string) xmalloc (c);
      strncpy (user, name + 1, c - 1);
      user[c - 1] = 0;
      
      /* We only need the cast here for (deficient) systems
         which do not declare `getpwnam' in <pwd.h>.  */
      p = (struct passwd *) getpwnam (user);
      free (user);

      /* If no such user, just use `.'.  */
      home = p ? p->pw_dir : ".";
      if (IS_DIR_SEP (*home) && IS_DIR_SEP (home[1])) { /* handle leading // */
        home++;
      }
      if (IS_DIR_SEP (home[strlen (home) - 1]) && name[c] != 0)
        c++; /* If HOME ends in /, omit the / after ~user. */

      expansion = concat3 (prefix, home, name + c);
#else /* not HAVE_PWD_H */
      /* Since we don't know how to look up a user name, just return the
         original string. */
      if (*prefix)
        name -= 2;
      expansion = name;
#endif /* not HAVE_PWD_H */
  }
  /* We may return the same thing as the original, and then we might not
     be returning a malloc-ed string.  Callers beware.  Sorry.  */
  return (string) expansion;
}

#if defined (KPSE_COMPAT_API)
string
kpse_tilde_expand (const_string name)
{
    return kpathsea_tilde_expand (kpse_def, name);
}
#endif

#ifdef TEST

void
test_expand_tilde (const_string filename)
{
  string answer;
  
  printf ("Tilde expansion of `%s':\t", filename ? filename : "(nil)");
  answer = kpse_tilde_expand (filename);
  puts (answer);
}

int
main (int argc, char **argv)
{
  string tilde_path = "tilde";
  kpse_set_program_name(argv[0],NULL);
  test_expand_tilde ("");
  test_expand_tilde ("none");
  test_expand_tilde ("~root");
  test_expand_tilde ("~");
  test_expand_tilde ("foo~bar");

  test_expand_tilde ("!!");
  test_expand_tilde ("!!none");
  test_expand_tilde ("!!~root");
  test_expand_tilde ("!!~");
  test_expand_tilde ("!!foo~bar");
  
  return 0;
}

#endif /* TEST */


/*
Local variables:
standalone-compile-command: "gcc -g -I. -I.. -DTEST tilde.c kpathsea.a"
End:
*/