/src/tmux/environ.c

Source
/* $OpenBSD: environ.c,v 1.31 2026/06/13 20:07:30 nicm Exp $ */

/*
 * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <fnmatch.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "tmux.h"

/*
 * Environment - manipulate a set of environment variables.
 */

RB_HEAD(environ, environ_entry);
static int environ_cmp(struct environ_entry *, struct environ_entry *);
RB_GENERATE_STATIC(environ, environ_entry, entry, environ_cmp);

static int
environ_cmp(struct environ_entry *envent1, struct environ_entry *envent2)
{
  return (strcmp(envent1->name, envent2->name));
}

/* Initialise the environment. */
struct environ *
environ_create(void)
{
  struct environ  *env;

  env = xcalloc(1, sizeof *env);
  RB_INIT(env);

  return (env);
}

/* Free an environment. */
void
environ_free(struct environ *env)
{
  struct environ_entry  *envent, *envent1;

  if (env == NULL)
    return;

  RB_FOREACH_SAFE(envent, environ, env, envent1) {
    RB_REMOVE(environ, env, envent);
    free(envent->name);
    free(envent->value);
    free(envent);
  }
  free(env);
}

struct environ_entry *
environ_first(struct environ *env)
{
  return (RB_MIN(environ, env));
}

struct environ_entry *
environ_next(struct environ_entry *envent)
{
  return (RB_NEXT(environ, env, envent));
}

/* Copy one environment into another. */
void
environ_copy(struct environ *srcenv, struct environ *dstenv)
{
  struct environ_entry  *envent;

  RB_FOREACH(envent, environ, srcenv) {
    if (envent->value == NULL)
      environ_clear(dstenv, envent->name);
    else {
      environ_set(dstenv, envent->name, envent->flags,
          "%s", envent->value);
    }
  }
}

/* Find an environment variable. */
struct environ_entry *
environ_find(struct environ *env, const char *name)
{
  struct environ_entry  envent;

  envent.name = (char *) name;
  return (RB_FIND(environ, env, &envent));
}

/* Set an environment variable. */
void
environ_set(struct environ *env, const char *name, int flags, const char *fmt,
    ...)
{
  struct environ_entry  *envent;
  va_list      ap;

  va_start(ap, fmt);
  if ((envent = environ_find(env, name)) != NULL) {
    envent->flags = flags;
    free(envent->value);
    xvasprintf(&envent->value, fmt, ap);
  } else {
    envent = xmalloc(sizeof *envent);
    envent->name = xstrdup(name);
    envent->flags = flags;
    xvasprintf(&envent->value, fmt, ap);
    RB_INSERT(environ, env, envent);
  }
  va_end(ap);
}

/* Clear an environment variable. */
void
environ_clear(struct environ *env, const char *name)
{
  struct environ_entry  *envent;

  if ((envent = environ_find(env, name)) != NULL) {
    free(envent->value);
    envent->value = NULL;
  } else {
    envent = xmalloc(sizeof *envent);
    envent->name = xstrdup(name);
    envent->flags = 0;
    envent->value = NULL;
    RB_INSERT(environ, env, envent);
  }
}

/* Set an environment variable from a NAME=VALUE string. */
void
environ_put(struct environ *env, const char *var, int flags)
{
  char    *name;
  const char  *value;

  value = strchr(var, '=');
  if (value == NULL)
    return;
  value++;

  name = xstrdup(var);
  name[strcspn(name, "=")] = '\0';

  environ_set(env, name, flags, "%s", value);
  free(name);
}

/* Unset an environment variable. */
void
environ_unset(struct environ *env, const char *name)
{
  struct environ_entry  *envent;

  if ((envent = environ_find(env, name)) == NULL)
    return;
  RB_REMOVE(environ, env, envent);
  free(envent->name);
  free(envent->value);
  free(envent);
}

/* Copy variables from a destination into a source environment. */
void
environ_update(struct options *oo, struct environ *src, struct environ *dst)
{
  struct environ_entry    *envent;
  struct environ_entry    *envent1;
  struct options_entry    *o;
  struct options_array_item *a;
  union options_value   *ov;
  int        found;

  o = options_get(oo, "update-environment");
  if (o == NULL)
    return;
  a = options_array_first(o);
  while (a != NULL) {
    ov = options_array_item_value(a);
    found = 0;
    RB_FOREACH_SAFE(envent, environ, src, envent1) {
      if (fnmatch(ov->string, envent->name, 0) == 0) {
        environ_set(dst, envent->name, 0, "%s", envent->value);
        found = 1;
      }
    }
    if (!found)
      environ_clear(dst, ov->string);
    a = options_array_next(a);
  }
}

/* Push environment into the real environment - use after fork(). */
void
environ_push(struct environ *env)
{
  struct environ_entry  *envent;

  environ = xcalloc(1, sizeof *environ);
  RB_FOREACH(envent, environ, env) {
    if (envent->value != NULL &&
        *envent->name != '\0' &&
        (~envent->flags & ENVIRON_HIDDEN))
      setenv(envent->name, envent->value, 1);
  }
}

/* Log the environment. */
void
environ_log(struct environ *env, const char *fmt, ...)
{
  struct environ_entry  *envent;
  va_list      ap;
  char      *prefix;

  va_start(ap, fmt);
  vasprintf(&prefix, fmt, ap);
  va_end(ap);

  RB_FOREACH(envent, environ, env) {
    if (envent->value != NULL && *envent->name != '\0') {
      log_debug("%s%s=%s", prefix, envent->name,
          envent->value);
    }
  }

  free(prefix);
}

/* Create initial environment for new child. */
struct environ *
environ_for_session(struct session *s, int no_TERM)
{
  struct environ  *env;
  const char  *value;
  int    idx;

  env = environ_create();
  environ_copy(global_environ, env);
  if (s != NULL)
    environ_copy(s->environ, env);

  if (!no_TERM) {
    value = options_get_string(global_options, "default-terminal");
    environ_set(env, "TERM", 0, "%s", value);
    environ_set(env, "TERM_PROGRAM", 0, "%s", "tmux");
    environ_set(env, "TERM_PROGRAM_VERSION", 0, "%s", getversion());
    environ_set(env, "COLORTERM", 0, "truecolor");
  }

#ifdef HAVE_SYSTEMD
  environ_clear(env, "LISTEN_PID");
  environ_clear(env, "LISTEN_FDS");
  environ_clear(env, "LISTEN_FDNAMES");
#endif

  if (s != NULL)
    idx = s->id;
  else
    idx = -1;
  environ_set(env, "TMUX", 0, "%s,%ld,%d", socket_path, (long)getpid(),
      idx);

  return (env);
}

Coverage Report

Created: 2026-07-16 06:55