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putenv(3)
NAME
  putenv - Sets an environment variable

SYNOPSIS
  #include <stdlib.h>

  int putenv(
	  const char *string );

  The following syntax is for XSH5.0-compliant interfaces:

  #include <stdlib.h>

  int putenv(
	  char *string );

LIBRARY
  Standard C Library (libc)

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  putenv(): XSH4.0, XSH4.2, XSH5.0, POSIX.1

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

PARAMETERS
  string
      Points to a name=value string.

DESCRIPTION
  The putenv() function sets the value of an environment variable by altering
  an existing variable or by creating a new one. The new environment variable
  remains in effect even after the program setting it is exited.

  The string parameter points to a string of the form "name=value", where
  name is the environment variable and value is the new value for it.

NOTES
  The putenv() function manipulates the environ external variable, and it can
  be used in conjunction with the getenv() function. However, the third
  parameter to the main function (the environment pointer) is not changed.

  The putenv() function uses the malloc() function to enlarge the
  environment.

  A potential error is to call putenv() with an automatic variable as the
  argument and then exit the calling function while string is still part of
  the environment.

RETURN VALUES
  Upon successful completion, a value of 0 (zero) is returned. If the
  malloc() function is unable to obtain sufficient space to expand the
  environment, the putenv() function returns a nonzero value.

SEE ALSO
  Functions: clearenv(3), exec(2), getenv(3), malloc(3)

  Standards: standards(5)

Index for Section 3

Alphabetical listing for P

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