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[gnulib.git] / lib / getusershell.c

diff --git a/lib/getusershell.c b/lib/getusershell.c
index 35f72db..c026ec0 100644 (file)
--- a/lib/getusershell.c
+++ b/lib/getusershell.c
@@ -1,5 +1,5 @@
 /* getusershell.c -- Return names of valid user shells.
-   Copyright (C) 1991, 1997, 2000 Free Software Foundation, Inc.
+   Copyright (C) 1991, 1997, 2000, 2001, 2003 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -22,12 +22,19 @@
 #endif
 
 #ifndef SHELLS_FILE
+# ifndef __DJGPP__
 /* File containing a list of nonrestricted shells, one per line. */
-# define SHELLS_FILE "/etc/shells"
+#  define SHELLS_FILE "/etc/shells"
+# else
+/* This is a horrible kludge.  Isn't there a better way?  */
+#  define SHELLS_FILE "/dev/env/DJDIR/etc/shells"
+# endif
 #endif
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <ctype.h>
+#include "unlocked-io.h"
 #include "xalloc.h"
 
 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
@@ -38,17 +45,25 @@
 
 #define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c))
 
-static int readname ();
+static size_t readname (char **, size_t *, FILE *);
+
+#if ! defined ADDITIONAL_DEFAULT_SHELLS && defined __MSDOS__
+# define ADDITIONAL_DEFAULT_SHELLS \
+  "c:/dos/command.com", "c:/windows/command.com", "c:/command.com",
+#else
+# define ADDITIONAL_DEFAULT_SHELLS /* empty */
+#endif
 
 /* List of shells to use if the shells file is missing. */
 static char const* const default_shells[] =
 {
+  ADDITIONAL_DEFAULT_SHELLS
   "/bin/sh", "/bin/csh", "/usr/bin/sh", "/usr/bin/csh", NULL
 };
 
 /* Index of the next shell in `default_shells' to return.
    0 means we are not using `default_shells'. */
-static int default_index = 0;
+static size_t default_index = 0;
 
 /* Input stream from the shells file. */
 static FILE *shellstream = NULL;
@@ -57,7 +72,7 @@ static FILE *shellstream = NULL;
 static char *line = NULL;
 
 /* Number of bytes allocated for `line'. */
-static int line_size = 0;
+static size_t line_size = 0;
 \f
 /* Return an entry from the shells file, ignoring comment lines.
    If the file doesn't exist, use the list in DEFAULT_SHELLS (above).
@@ -65,7 +80,7 @@ static int line_size = 0;
    Return NULL if there are no more entries.  */
 
 char *
-getusershell ()
+getusershell (void)
 {
   if (default_index > 0)
     {
@@ -97,19 +112,17 @@ getusershell ()
 /* Rewind the shells file. */
 
 void
-setusershell ()
+setusershell (void)
 {
   default_index = 0;
-  if (shellstream == NULL)
-    shellstream = fopen (SHELLS_FILE, "r");
-  else
-    fseek (shellstream, 0L, 0);
+  if (shellstream)
+    rewind (shellstream);
 }
 
 /* Close the shells file. */
 
 void
-endusershell ()
+endusershell (void)
 {
   if (shellstream)
     {
@@ -123,22 +136,22 @@ endusershell ()
    and/or realloc'd as necessary and can start out NULL,
    and whose size is passed and returned in *SIZE.
 
-   Return the number of characters placed in *NAME
+   Return the number of bytes placed in *NAME
    if some nonempty sequence was found, otherwise 0.  */
 
-static int
-readname (name, size, stream)
-     char **name;
-     int *size;
-     FILE *stream;
+static size_t
+readname (char **name, size_t *size, FILE *stream)
 {
   int c;
-  int name_index = 0;
+  size_t name_index = 0;
 
   if (*name == NULL)
     {
-      *size = 10;
-      *name = (char *) xmalloc (*size);
+      /* The initial size must be a power of two, so that the overflow
+        check works.  */
+      *size = 16;
+
+      *name = xmalloc (*size);
     }
 
   /* Skip blank space.  */
@@ -148,10 +161,12 @@ readname (name, size, stream)
   while (c != EOF && !ISSPACE (c))
     {
       (*name)[name_index++] = c;
-      while (name_index >= *size)
+      if (*size < name_index)
        {
          *size *= 2;
-         *name = (char *) xrealloc (*name, *size);
+         if (! *size)
+           xalloc_die ();
+         *name = xrealloc (*name, *size);
        }
       c = getc (stream);
     }
@@ -160,7 +175,8 @@ readname (name, size, stream)
 }
 
 #ifdef TEST
-main ()
+int
+main (void)
 {
   char *s;