examples/loadables/basename.c

   1 /* basename - return nondirectory portion of pathname */
   2
   3 /* See Makefile for compilation details. */
   4
   5 #include "config.h"
   6
   7 #if defined (HAVE_UNISTD_H)
   8 #  include <unistd.h>
   9 #endif
  10
  11 #include <stdio.h>
  12 #include "builtins.h"
  13 #include "shell.h"
  14 #include "common.h"
  15
  16 basename_builtin (list)
  17      WORD_LIST *list;
  18 {
  19   int slen, sufflen, off;
  20   char *string, *suffix, *fn;
  21
  22   if (list == 0)
  23     {
  24       builtin_usage ();
  25       return (EX_USAGE);
  26     }
  27
  28   if (no_options (list))
  29     return (EX_USAGE);
  30
  31   string = list->word->word;
  32   suffix = (char *)NULL;
  33   if (list->next)
  34     {
  35       list = list->next;
  36       suffix = list->word->word;
  37     }
  38
  39   if (list->next)
  40     {
  41       builtin_usage ();
  42       return (EX_USAGE);
  43     }
  44
  45   slen = strlen (string);
  46
  47   /* Strip trailing slashes */
  48   while (slen > 0 && string[slen - 1] == '/')
  49     slen--;
  50
  51   /* (2) If string consists entirely of slash characters, string shall be
  52          set to a single slash character.  In this case, skip steps (3)
  53          through (5). */
  54   if (slen == 0)
  55     {
  56       fputs ("/\n", stdout);
  57       return (EXECUTION_SUCCESS);
  58     }
  59
  60   /* (3) If there are any trailing slash characters in string, they
  61          shall be removed. */
  62   string[slen] = '\0';
  63
  64   /* (4) If there are any slash characters remaining in string, the prefix
  65          of string up to an including the last slash character in string
  66          shall be removed. */
  67   while (--slen >= 0)
  68     if (string[slen] == '/')
  69       break;
  70
  71   fn = string + slen + 1;
  72
  73   /* (5) If the suffix operand is present, is not identical to the
  74          characters remaining in string, and is identical to a suffix
  75          of the characters remaining in string, the suffix suffix
  76          shall be removed from string.  Otherwise, string shall not be
  77          modified by this step. */
  78   if (suffix)
  79     {
  80       sufflen = strlen (suffix);
  81       slen = strlen (fn);
  82       if (sufflen < slen)
  83         {
  84           off = slen - sufflen;
  85           if (strcmp (fn + off, suffix) == 0)
  86             fn[off] = '\0';
  87         }
  88     }
  89   printf ("%s\n", fn);
  90   return (EXECUTION_SUCCESS);
  91 }
  92
  93 char *basename_doc[] = {
  94         "Return non-directory portion of pathname.",
  95         "",
  96         "The STRING is converted to a filename corresponding to the last",
  97         "pathname component in STRING.  If the suffix string SUFFIX is",
  98         "supplied, it is removed.",
  99         (char *)NULL
 100 };
 101
 102 /* The standard structure describing a builtin command.  bash keeps an array
 103    of these structures. */
 104 struct builtin basename_struct = {
 105         "basename",             /* builtin name */
 106         basename_builtin,       /* function implementing the builtin */
 107         BUILTIN_ENABLED,        /* initial flags for builtin */
 108         basename_doc,           /* array of long documentation strings. */
 109         "basename string [suffix]",     /* usage synopsis */
 110         0                       /* reserved for internal use */
 111 };