envlist.c File Reference

Private copy of the environment variables. More...

#include "config.h"
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include "envlist.h"
#include "memory.h"
#include "string2.h"

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Functions
void	envlist_free (char ***envp)
	Free the private copy of the environment.
char **	envlist_init (char **envp)
	Create a copy of the environment.
bool	envlist_set (char ***envp, const char *name, const char *value, bool overwrite)
	Set an environment variable.
bool	envlist_unset (char ***envp, const char *name)
	Unset an environment variable.

Detailed Description

Private copy of the environment variables.

Authors

• Richard Russon
• Pietro Cerutti

Copyright

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, see http://www.gnu.org/licenses/.

Definition in file envlist.c.

Function Documentation

envlist_free()

void envlist_free

(

char ***

envp

)

Free the private copy of the environment.

Parameters

envp	Environment to free

Definition at line 42 of file envlist.c.

{
  if (!envp || !*envp)
    return;
 
  for (char **p = *envp; p && *p; p++)
    FREE(p);
 
  FREE(envp);
}

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envlist_init()

char ** envlist_init

(

char **

envp

)

Create a copy of the environment.

Parameters

envp	Environment to copy

Return values

ptr	Copy of the environment

Definition at line 58 of file envlist.c.

{
  if (!envp)
    return NULL;
 
  char **src = NULL;
  char **dst = NULL;
  int count = 0;
  for (src = envp; src && *src; src++)
    count++;
 
  char **env_copy = MUTT_MEM_CALLOC(count + 1, char *);
  for (src = envp, dst = env_copy; src && *src; src++, dst++)
    *dst = mutt_str_dup(*src);
 
  return env_copy;
}

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envlist_set()

bool envlist_set	(	char ***	envp,
		const char *	name,
		const char *	value,
		bool	overwrite )

Set an environment variable.

Parameters

envp	Environment to modify
name	Name of the variable
value	New value
overwrite	Should the variable be overwritten?

Return values

true	Success: variable set, or overwritten
false	Variable exists and overwrite was false

It's broken out because some other parts of neomutt (filter.c) need to set/overwrite environment variables in NeoMutt->env before calling exec().

Definition at line 88 of file envlist.c.

{
  if (!envp || !*envp || !name || (name[0] == '\0'))
    return false;
 
  // Find a matching entry
  int count = 0;
  int match = -1;
  char *str = NULL;
  for (; (str = (*envp)[count]); count++)
  {
    size_t len = mutt_str_startswith(str, name);
    if ((len != 0) && (str[len] == '='))
    {
      if (!overwrite)
        return false;
      match = count;
      break;
    }
  }
 
  // Format var=value string dynamically to avoid truncation
  const char *val = NONULL(value);
  size_t nlen = mutt_str_len(name);
  size_t vlen = mutt_str_len(val);
  char *work = MUTT_MEM_MALLOC(nlen + 1 + vlen + 1, char);
  snprintf(work, nlen + 1 + vlen + 1, "%s=%s", name, val);
 
  if (match >= 0)
  {
    // match found, overwrite
    FREE(&(*envp)[match]);
    (*envp)[match] = work;
  }
  else
  {
    // not found, add a new entry
    MUTT_MEM_REALLOC(envp, count + 2, char *);
    (*envp)[count] = work;
    (*envp)[count + 1] = NULL;
  }
 
  return true;
}

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envlist_unset()

bool envlist_unset	(	char ***	envp,
		const char *	name )

Unset an environment variable.

Parameters

envp	Environment to modify
name	Variable to unset

Return values

true	Success: Variable unset
false	Error: Variable doesn't exist

Definition at line 140 of file envlist.c.

{
  if (!envp || !*envp || !name || (name[0] == '\0'))
    return false;
 
  int count = 0;
  for (; (*envp)[count]; count++)
    ; // do nothing
 
  char *str = NULL;
  for (int match = 0; (str = (*envp)[match]); match++)
  {
    size_t len = mutt_str_startswith(str, name);
    if ((len != 0) && (str[len] == '='))
    {
      FREE(&(*envp)[match]);
      // Move down the later entries
      memmove(&(*envp)[match], &(*envp)[match + 1], (count - match) * sizeof(char *));
      // Shrink the array
      MUTT_MEM_REALLOC(envp, count, char *);
      return true;
    }
  }
  return false;
}

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