Tcl_PutEnv(3) Tcl Library Procedures Tcl_PutEnv(3)__________________________________________________________________________________________________________________________________________________NAME
Tcl_PutEnv - procedures to manipulate the environment
const char *assignment (in) Info about environment variable in the format "NAME=value". The assignment argument is in the system
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.
Tcl 7.5 Tcl_PutEnv(3)
Check Out this Related Man Page
putenv(3C) Standard C Library Functions putenv(3C)NAME
putenv - change or add value to environment
int putenv(char *string);
The putenv() function 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 string argument points to a string of the form name=value. The space used by string is no longer used once a new string-defining name
is passed to putenv().
The putenv() function uses malloc(3C) to enlarge the environment.
After putenv() is called, environment variables are not in alphabetical order.
Upon successful completion, putenv() returns 0. Otherwise, it returns a non-zero value and sets errno to indicate the error.
The putenv() function may fail if:
ENOMEM Insufficient memory was available.
The putenv() function can be safely called from multithreaded programs. Caution must be exercised when using this function and getenv(3C)
in multithreaded programs. These functions examine and modify the environment list, which is shared by all threads in a program. The sys-
tem prevents the list from being accessed simultaneously by two different threads. It does not, however, prevent two threads from succes-
sively accessing the environment list using putenv() or getenv().
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|Interface Stability |Standard |
|MT-Level |Safe |
SEE ALSO exec(2), getenv(3C), malloc(3C), attributes(5), environ(5), standards(5)WARNINGS
The string argument should not be an automatic variable. It should be declared static if it is declared within a function because it can-
not be automatically declared. A potential error is to call putenv() with a pointer to an automatic variable as the argument and to then
exit the calling function while string is still part of the environment.
SunOS 5.11 7 Aug 2004 putenv(3C)
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