PUTENV(3C)                           SysV                           PUTENV(3C)



NAME
     putenv - change or add value to environment

SYNOPSIS
     int putenv (string)
     char *string;

DESCRIPTION
     string points to a string of the form ``name=value.''  putenv makes the
     value of the environment variable name equal to value by altering an
     existing variable or creating a new one.  In either case, the string
     pointed to by string becomes part of the environment, so altering the
     string will change the environment.  The space used by string is no
     longer used once a new string-defining name is passed to putenv.

SEE ALSO
     exec(2), getenv(3C), malloc(3C), environ(5).

DIAGNOSTICS
     putenv returns nonzero if it was unable to obtain enough space via malloc
     for an expanded environment, otherwise zero.

WARNINGS
     putenv manipulates the environment pointed to by environ, and can be used
     in conjunction with getenv.  However, envp (the third argument to main)
     is not changed.
     This routine uses malloc(3C) to enlarge the environment.
     After putenv is called, environmental variables are not in alphabetical
     order.
     A potential error is to call putenv with an automatic variable as the
     argument, then exit the calling function while string is still part of
     the environment.