examples/loadables/basename.c

   1 /* basename - return nondirectory portion of pathname */
   2
   3 /* See Makefile for compilation details. */
   4
   5 /*
   6    Copyright (C) 1999-2020 Free Software Foundation, Inc.
   7
   8    This file is part of GNU Bush.
   9    Bush is free software: you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation, either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    Bush is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with Bush.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "config.h"
  24
  25 #if defined (HAVE_UNISTD_H)
  26 #  include <unistd.h>
  27 #endif
  28
  29 #include <stdio.h>
  30 #include "builtins.h"
  31 #include "shell.h"
  32 #include "common.h"
  33 #include "bushgetopt.h"
  34
  35 int
  36 basename_builtin (list)
  37      WORD_LIST *list;
  38 {
  39   int slen, sufflen, off;
  40   char *string, *suffix, *fn;
  41
  42   if (no_options (list))
  43     return (EX_USAGE);
  44   list = loptend;
  45   if (list == 0)
  46     {
  47       builtin_usage ();
  48       return (EX_USAGE);
  49     }
  50
  51   string = list->word->word;
  52   suffix = (char *)NULL;
  53   if (list->next)
  54     {
  55       list = list->next;
  56       suffix = list->word->word;
  57     }
  58
  59   if (list->next)
  60     {
  61       builtin_usage ();
  62       return (EX_USAGE);
  63     }
  64
  65   slen = strlen (string);
  66
  67   /* Strip trailing slashes */
  68   while (slen > 0 && string[slen - 1] == '/')
  69     slen--;
  70
  71   /* (2) If string consists entirely of slash characters, string shall be
  72          set to a single slash character.  In this case, skip steps (3)
  73          through (5). */
  74   if (slen == 0)
  75     {
  76       fputs ("/\n", stdout);
  77       return (EXECUTION_SUCCESS);
  78     }
  79
  80   /* (3) If there are any trailing slash characters in string, they
  81          shall be removed. */
  82   string[slen] = '\0';
  83
  84   /* (4) If there are any slash characters remaining in string, the prefix
  85          of string up to an including the last slash character in string
  86          shall be removed. */
  87   while (--slen >= 0)
  88     if (string[slen] == '/')
  89       break;
  90
  91   fn = string + slen + 1;
  92
  93   /* (5) If the suffix operand is present, is not identical to the
  94          characters remaining in string, and is identical to a suffix
  95          of the characters remaining in string, the suffix suffix
  96          shall be removed from string.  Otherwise, string shall not be
  97          modified by this step. */
  98   if (suffix)
  99     {
 100       sufflen = strlen (suffix);
 101       slen = strlen (fn);
 102       if (sufflen < slen)
 103         {
 104           off = slen - sufflen;
 105           if (strcmp (fn + off, suffix) == 0)
 106             fn[off] = '\0';
 107         }
 108     }
 109   printf ("%s\n", fn);
 110   return (EXECUTION_SUCCESS);
 111 }
 112
 113 char *basename_doc[] = {
 114         "Return non-directory portion of pathname.",
 115         "",
 116         "The STRING is converted to a filename corresponding to the last",
 117         "pathname component in STRING.  If the suffix string SUFFIX is",
 118         "supplied, it is removed.",
 119         (char *)NULL
 120 };
 121
 122 /* The standard structure describing a builtin command.  bush keeps an array
 123    of these structures. */
 124 struct builtin basename_struct = {
 125         "basename",             /* builtin name */
 126         basename_builtin,       /* function implementing the builtin */
 127         BUILTIN_ENABLED,        /* initial flags for builtin */
 128         basename_doc,           /* array of long documentation strings. */
 129         "basename string [suffix]",     /* usage synopsis */
 130         0                       /* reserved for internal use */
 131 };