minix/external/bsd/kyua-testers/dist/env.c

// Copyright 2012 Google Inc.
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//
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// modification, are permitted provided that the following conditions are
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//
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//   notice, this list of conditions and the following disclaimer.
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//   notice, this list of conditions and the following disclaimer in the
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//   may be used to endorse or promote products derived from this software
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#if defined(HAVE_CONFIG_H)
#   include "config.h"
#endif

#include "env.h"

#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "error.h"


/// Sets an environment variable.
///
/// \param name Name of the environment variable to set.
/// \param value Value to be set.
///
/// \return An error object.
kyua_error_t
kyua_env_set(const char* name, const char* value)
{
    kyua_error_t error;

#if defined(HAVE_SETENV)
    if (setenv(name, value, 1) == -1)
        error = kyua_libc_error_new(
            errno, "Failed to set environment variable %s to %s", name, value);
    else
        error = kyua_error_ok();
#elif defined(HAVE_PUTENV)
    const size_t length = strlen(name) + strlen(value) + 2;
    char* buffer = (char*)malloc(length);
    if (buffer == NULL)
        error = kyua_oom_error_new();
    else {
        const size_t printed_length = snprintf(buffer, length, "%s=%s", name,
                                               value);
        assert(length == printed_length + 1);
        if (putenv(buffer) == -1) {
            error = kyua_libc_error_new(
                errno, "Failed to set environment variable %s to %s",
                name, value);
            free(buffer);
        } else
            error = kyua_error_ok();
    }
#else
#   error "Don't know how to set an environment variable."
#endif

    return error;
}


/// Unsets an environment variable.
///
/// \param name Name of the environment variable to unset.
///
/// \return An error object.
kyua_error_t
kyua_env_unset(const char* name)
{
#if defined(HAVE_UNSETENV)
    if (unsetenv(name) == -1)
        return kyua_libc_error_new(
            errno, "Failed to unset environment variable %s", name);
    else
        return kyua_error_ok();
#elif defined(HAVE_PUTENV)
    return kyua_env_set(name, "");
#else
#   error "Don't know how to unset an environment variable."
#endif
}