Back to index

nagios-plugins  1.4.16
Defines | Functions | Variables
setenv.c File Reference
#include <config.h>
#include <alloca.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include "malloca.h"

Go to the source code of this file.

Defines

#define _GL_ARG_NONNULL(params)
#define __set_errno(ev)   ((errno) = (ev))
#define __environ   environ
#define LOCK
#define UNLOCK
#define KNOWN_VALUE(Str)   NULL
#define STORE_VALUE(Str)   do { } while (0)

Functions

int __add_to_environ (const char *name, const char *value, const char *combined, int replace)
int setenv (const char *name, const char *value, int replace)
int clearenv (void)

Variables

static char ** last_environ

Define Documentation

#define __environ   environ

Definition at line 47 of file setenv.c.

#define __set_errno (   ev)    ((errno) = (ev))

Definition at line 32 of file setenv.c.

#define _GL_ARG_NONNULL (   params)

Definition at line 23 of file setenv.c.

#define KNOWN_VALUE (   Str)    NULL

Definition at line 98 of file setenv.c.

#define LOCK

Definition at line 57 of file setenv.c.

#define STORE_VALUE (   Str)    do { } while (0)

Definition at line 99 of file setenv.c.

#define UNLOCK

Definition at line 58 of file setenv.c.


Function Documentation

int __add_to_environ ( const char *  name,
const char *  value,
const char *  combined,
int  replace 
)

Definition at line 116 of file setenv.c.

{
  char **ep;
  size_t size;
  const size_t namelen = strlen (name);
  const size_t vallen = value != NULL ? strlen (value) + 1 : 0;

  LOCK;

  /* We have to get the pointer now that we have the lock and not earlier
     since another thread might have created a new environment.  */
  ep = __environ;

  size = 0;
  if (ep != NULL)
    {
      for (; *ep != NULL; ++ep)
        if (!strncmp (*ep, name, namelen) && (*ep)[namelen] == '=')
          break;
        else
          ++size;
    }

  if (ep == NULL || *ep == NULL)
    {
      char **new_environ;
#ifdef USE_TSEARCH
      char *new_value;
#endif

      /* We allocated this space; we can extend it.  */
      new_environ =
        (char **) (last_environ == NULL
                   ? malloc ((size + 2) * sizeof (char *))
                   : realloc (last_environ, (size + 2) * sizeof (char *)));
      if (new_environ == NULL)
        {
          /* It's easier to set errno to ENOMEM than to rely on the
             'malloc-posix' and 'realloc-posix' gnulib modules.  */
          __set_errno (ENOMEM);
          UNLOCK;
          return -1;
        }

      /* If the whole entry is given add it.  */
      if (combined != NULL)
        /* We must not add the string to the search tree since it belongs
           to the user.  */
        new_environ[size] = (char *) combined;
      else
        {
          /* See whether the value is already known.  */
#ifdef USE_TSEARCH
# ifdef _LIBC
          new_value = (char *) alloca (namelen + 1 + vallen);
          __mempcpy (__mempcpy (__mempcpy (new_value, name, namelen), "=", 1),
                     value, vallen);
# else
          new_value = (char *) malloca (namelen + 1 + vallen);
          if (new_value == NULL)
            {
              __set_errno (ENOMEM);
              UNLOCK;
              return -1;
            }
          memcpy (new_value, name, namelen);
          new_value[namelen] = '=';
          memcpy (&new_value[namelen + 1], value, vallen);
# endif

          new_environ[size] = KNOWN_VALUE (new_value);
          if (new_environ[size] == NULL)
#endif
            {
              new_environ[size] = (char *) malloc (namelen + 1 + vallen);
              if (new_environ[size] == NULL)
                {
#if defined USE_TSEARCH && !defined _LIBC
                  freea (new_value);
#endif
                  __set_errno (ENOMEM);
                  UNLOCK;
                  return -1;
                }

#ifdef USE_TSEARCH
              memcpy (new_environ[size], new_value, namelen + 1 + vallen);
#else
              memcpy (new_environ[size], name, namelen);
              new_environ[size][namelen] = '=';
              memcpy (&new_environ[size][namelen + 1], value, vallen);
#endif
              /* And save the value now.  We cannot do this when we remove
                 the string since then we cannot decide whether it is a
                 user string or not.  */
              STORE_VALUE (new_environ[size]);
            }
#if defined USE_TSEARCH && !defined _LIBC
          freea (new_value);
#endif
        }

      if (__environ != last_environ)
        memcpy ((char *) new_environ, (char *) __environ,
                size * sizeof (char *));

      new_environ[size + 1] = NULL;

      last_environ = __environ = new_environ;
    }
  else if (replace)
    {
      char *np;

      /* Use the user string if given.  */
      if (combined != NULL)
        np = (char *) combined;
      else
        {
#ifdef USE_TSEARCH
          char *new_value;
# ifdef _LIBC
          new_value = alloca (namelen + 1 + vallen);
          __mempcpy (__mempcpy (__mempcpy (new_value, name, namelen), "=", 1),
                     value, vallen);
# else
          new_value = malloca (namelen + 1 + vallen);
          if (new_value == NULL)
            {
              __set_errno (ENOMEM);
              UNLOCK;
              return -1;
            }
          memcpy (new_value, name, namelen);
          new_value[namelen] = '=';
          memcpy (&new_value[namelen + 1], value, vallen);
# endif

          np = KNOWN_VALUE (new_value);
          if (np == NULL)
#endif
            {
              np = (char *) malloc (namelen + 1 + vallen);
              if (np == NULL)
                {
#if defined USE_TSEARCH && !defined _LIBC
                  freea (new_value);
#endif
                  __set_errno (ENOMEM);
                  UNLOCK;
                  return -1;
                }

#ifdef USE_TSEARCH
              memcpy (np, new_value, namelen + 1 + vallen);
#else
              memcpy (np, name, namelen);
              np[namelen] = '=';
              memcpy (&np[namelen + 1], value, vallen);
#endif
              /* And remember the value.  */
              STORE_VALUE (np);
            }
#if defined USE_TSEARCH && !defined _LIBC
          freea (new_value);
#endif
        }

      *ep = np;
    }

  UNLOCK;

  return 0;
}

Here is the call graph for this function:

Here is the caller graph for this function:

int clearenv ( void  )

Definition at line 309 of file setenv.c.

{
  LOCK;

  if (__environ == last_environ && __environ != NULL)
    {
      /* We allocated this environment so we can free it.  */
      free (__environ);
      last_environ = NULL;
    }

  /* Clear the environment pointer removes the whole environment.  */
  __environ = NULL;

  UNLOCK;

  return 0;
}
int setenv ( const char *  name,
const char *  value,
int  replace 
)

Definition at line 294 of file setenv.c.

{
  if (name == NULL || *name == '\0' || strchr (name, '=') != NULL)
    {
      __set_errno (EINVAL);
      return -1;
    }

  return __add_to_environ (name, value, NULL, replace);
}

Here is the call graph for this function:

Here is the caller graph for this function:


Variable Documentation

char** last_environ [static]

Definition at line 106 of file setenv.c.