/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */

/*

 * Copyright (c) 1987 Regents of the University of California.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms are permitted

 * provided that the above copyright notice and this paragraph are

 * duplicated in all such forms and that any documentation,

 * advertising materials, and other materials related to such

 * distribution and use acknowledge that the software was developed

 * by the University of California, Berkeley.  The name of the

 * University may not be used to endorse or promote products derived

 * from this software without specific prior written permission.

 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED

 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

 */

/*

 * Copyright (c) 1987 Regents of the University of California.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms are permitted

 * provided that the above copyright notice and this paragraph are

 * duplicated in all such forms and that any documentation,

 * advertising materials, and other materials related to such

 * distribution and use acknowledge that the software was developed

 * by the University of California, Berkeley.  The name of the

 * University may not be used to endorse or promote products derived

 * from this software without specific prior written permission.

 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED

 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

 */

/* based on @(#)setenv.c        5.2 (Berkeley) 6/27/88 */

#include "autoconf.h"

#include <sys/types.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

static char *_findenv(char *, int *);

#ifndef HAVE_SETENV

extern int setenv(char *, char *, int);

#endif

#ifndef HAVE_UNSETENV

extern void unsetenv(char *);

#endif

/*

 * setenv --

 *      Set the value of the environmental variable "name" to be

 *      "value".  If rewrite is set, replace any current value.

 */

#ifndef HAVE_SETENV

int

setenv(name, value, rewrite)

    char *name, *value;

    int rewrite;

{

    extern char **environ;

    static int alloced;                     /* if allocated space before */

    char *C;

    int l_value, offset;

    if (*value == '=')                      /* no `=' in value */

        ++value;

    l_value = strlen(value);

    if ((C = _findenv(name, &offset))) {    /* find if already exists */

        if (!rewrite)

            return(0);

        if (strlen(C) >= l_value) {     /* old larger; copy over */

            while ((*C++ = *value++));

            return(0);

        }

    }

    else {                                  /* create new slot */

        int    cnt;

        char   **P;

        for (P = environ, cnt = 0; *P; ++P, ++cnt);

        if (alloced) {                  /* just increase size */

            environ = (char **)realloc((char *)environ,

                                       (u_int)(sizeof(char *) * (cnt + 2)));

            if (!environ)

                return(-1);

        }

        else {                          /* get new space */

            alloced = 1;            /* copy old entries into it */

            P = (char **)malloc((u_int)(sizeof(char *) *

                                        (cnt + 2)));

            if (!P)

                return(-1);

            memcpy(P, environ, cnt * sizeof(char *));

            environ = P;

        }

        environ[cnt + 1] = NULL;

        offset = cnt;

    }

    for (C = name; *C && *C != '='; ++C);   /* no `=' in name */

    if (!(environ[offset] =                 /* name + `=' + value */

          malloc((u_int)((int)(C - name) + l_value + 2))))

        return(-1);

    for (C = environ[offset]; (*C = *name++) &&( *C != '='); ++C);

    for (*C++ = '='; (*C++ = *value++) != NULL;);

    return(0);

}

#endif

/*

 * unsetenv(name) --

 *      Delete environmental variable "name".

 */

#ifndef HAVE_UNSETENV

void

unsetenv(name)

    char    *name;

{

    extern  char    **environ;

    char   **P;

    int     offset;

    while (_findenv(name, &offset))         /* if set multiple times */

        for (P = &environ[offset];; ++P)

            if (!(*P = *(P + 1)))

                break;

}

#endif

/* based on @(#)getenv.c        5.5 (Berkeley) 6/27/88 */

/*

 * getenv --

 *      Returns ptr to value associated with name, if any, else NULL.

 */

#ifndef HAVE_GETENV

char *

getenv(name)

    char *name;

{

    int offset;

    return(_findenv(name, &offset));

}

#endif

/*

 * _findenv --

 *      Returns pointer to value associated with name, if any, else NULL.

 *      Sets offset to be the offset of the name/value combination in the

 *      environmental array, for use by setenv(3) and unsetenv(3).

 *      Explicitly removes '=' in argument name.

 *

 */

static char *

_findenv(name, offset)

    char *name;

    int *offset;

{

    extern char **environ;

    int len;

    char **P, *C;

    for (C = name, len = 0; *C && *C != '='; ++C, ++len);

    for (P = environ; *P; ++P)

        if (!strncmp(*P, name, len))

            if (*(C = *P + len) == '=') {

                *offset = P - environ;

                return(++C);

            }

    return(NULL);

}