Initial creation of sourceware repository

gdb/environ.c

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+/* environ.c -- library for manipulating environments for GNU.
+   Copyright (C) 1986, 1989 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
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#define max(a, b) ((a) > (b) ? (a) : (b))
+
+#include "defs.h"
+#include "environ.h"
+#include "gdb_string.h"
+#include "gdbcore.h"
+
+
+/* Return a new environment object.  */
+
+struct environ *
+make_environ ()
+{
+  register struct environ *e;
+
+  e = (struct environ *) xmalloc (sizeof (struct environ));
+
+  e->allocated = 10;
+  e->vector = (char **) xmalloc ((e->allocated + 1) * sizeof (char *));
+  e->vector[0] = 0;
+  return e;
+}
+
+/* Free an environment and all the strings in it.  */
+
+void
+free_environ (e)
+     register struct environ *e;
+{
+  register char **vector = e->vector;
+
+  while (*vector)
+    free (*vector++);
+
+  free (e);
+}
+
+/* Copy the environment given to this process into E.
+   Also copies all the strings in it, so we can be sure
+   that all strings in these environments are safe to free.  */
+
+void
+init_environ (e)
+     register struct environ *e;
+{
+  extern char **environ;
+  register int i;
+
+  if (environ == NULL)
+    return;
+
+  for (i = 0; environ[i]; i++) /*EMPTY*/;
+
+  if (e->allocated < i)
+    {
+      e->allocated = max (i, e->allocated + 10);
+      e->vector = (char **) xrealloc ((char *)e->vector,
+				      (e->allocated + 1) * sizeof (char *));
+    }
+
+  memcpy (e->vector, environ, (i + 1) * sizeof (char *));
+
+  while (--i >= 0)
+    {
+      register int len = strlen (e->vector[i]);
+      register char *new = (char *) xmalloc (len + 1);
+      memcpy (new, e->vector[i], len + 1);
+      e->vector[i] = new;
+    }
+}
+
+/* Return the vector of environment E.
+   This is used to get something to pass to execve.  */
+
+char **
+environ_vector (e)
+     struct environ *e;
+{
+  return e->vector;
+}
+
+/* Return the value in environment E of variable VAR.  */
+
+char *
+get_in_environ (e, var)
+     const struct environ *e;
+     const char *var;
+{
+  register int len = strlen (var);
+  register char **vector = e->vector;
+  register char *s;
+
+  for (; (s = *vector) != NULL; vector++)
+    if (STREQN (s, var, len) && s[len] == '=')
+      return &s[len + 1];
+
+  return 0;
+}
+
+/* Store the value in E of VAR as VALUE.  */
+
+void
+set_in_environ (e, var, value)
+     struct environ *e;
+     const char *var;
+     const char *value;
+{
+  register int i;
+  register int len = strlen (var);
+  register char **vector = e->vector;
+  register char *s;
+
+  for (i = 0; (s = vector[i]) != NULL; i++)
+    if (STREQN (s, var, len) && s[len] == '=')
+      break;
+
+  if (s == 0)
+    {
+      if (i == e->allocated)
+	{
+	  e->allocated += 10;
+	  vector = (char **) xrealloc ((char *)vector,
+				       (e->allocated + 1) * sizeof (char *));
+	  e->vector = vector;
+	}
+      vector[i + 1] = 0;
+    }
+  else
+    free (s);
+
+  s = (char *) xmalloc (len + strlen (value) + 2);
+  strcpy (s, var);
+  strcat (s, "=");
+  strcat (s, value);
+  vector[i] = s;
+
+  /* This used to handle setting the PATH and GNUTARGET variables
+     specially.  The latter has been replaced by "set gnutarget"
+     (which has worked since GDB 4.11).  The former affects searching
+     the PATH to find SHELL, and searching the PATH to find the
+     argument of "symbol-file" or "exec-file".  Maybe we should have
+     some kind of "set exec-path" for that.  But in any event, having
+     "set env" affect anything besides the inferior is a bad idea.
+     What if we want to change the environment we pass to the program
+     without afecting GDB's behavior?  */
+
+  return;
+}
+
+/* Remove the setting for variable VAR from environment E.  */
+
+void
+unset_in_environ (e, var)
+     struct environ *e;
+     char *var;
+{
+  register int len = strlen (var);
+  register char **vector = e->vector;
+  register char *s;
+
+  for (; (s = *vector) != NULL; vector++)
+    {
+      if (STREQN (s, var, len) && s[len] == '=')
+	{
+	  free (s);
+	  /* Walk through the vector, shuffling args down by one, including
+	     the NULL terminator.  Can't use memcpy() here since the regions
+	     overlap, and memmove() might not be available. */
+	  while ((vector[0] = vector[1]) != NULL)
+	    {
+	      vector++;
+	    }
+	  break;
+	}
+    }
+}