| ActiveTcl User Guide |

## Tcl/Tk Documentation > TclLib > Environment

### Tcl/Tk Applications | Tcl Commands | Tk Commands | Tcl Library | Tk Library

### NAME

Tcl_PutEnv - procedures to manipulate the environment

### SYNOPSIS

#include <tcl.h>
int
Tcl_PutEnv(assignment)

### ARGUMENTS

const char *assignment (in)
  Info about environment variable in the format “NAME=value”. The assignment argument is in the system encoding.

### DESCRIPTION

Tcl_PutEnv sets an environment variable. The information is passed in a single string of the form “NAME=value”. This procedure is intended to be a stand-in for the UNIX putenv system call. All Tcl-based applications using putenv should redefine it to Tcl_PutEnv so that they will interface properly to the Tcl runtime.

### SEE ALSO

tclvars

### KEYWORDS

environment, variable
Copyright © 1995-1997 Roger E. Critchlow Jr. Copyright © 1997-1998 Sun Microsystems, Inc.