getenv()

Get the value of an environment variable

Synopsis:

#include <stdlib.h>

char* getenv( const char* name );

Library:

libc

Description:

The getenv() function searches the environment list for a string in the form name=value and returns a pointer to a string containing the value for the specified name. The matching is case-sensitive.

The returned string must not be modified by the calling process.

Returns:

A pointer to the value assigned to name, or NULL if name wasn't found in the environment.

Examples:

#include <stdio.h>
#include <stdlib.h>

int main( void )
{
    char* path;

    path = getenv( "INCLUDE" );
    if( path != NULL ) {
        printf( "INCLUDE=%s\n", path );
        return EXIT_SUCCESS;
    }
    
    return EXIT_FAILURE;
}

Classification:

ANSI, POSIX 1003.1a

Caveats:

The getenv() function manipulates the environment pointed to by the global environ variable.

See also:

clearenv(), environ, execl(), execle(), execlp(), execlpe(), execv(), execve(), execvp(), execvpe(), putenv(), searchenv(), setenv(), spawn*() functions, system()