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