SETENV(3) Linux Programmer’s Manual SETENV(3)
NAME
setenv - change or add an environment variable
SYNOPSIS
#include <stdlib.h>
int setenv(const char *name, const char *value, int overwrite);
int unsetenv(const char *name);
DESCRIPTION
The setenv() function adds the variable name to the environment with the value value, if name does not already
exist. If name does exist in the environment, then its value is changed to value if overwrite is non-zero; if
overwrite is zero, then the value of name is not changed.
The unsetenv() function deletes the variable name from the environment.
RETURN VALUE
The setenv() function returns zero on success, or -1 if there was insufficient space in the environment. The
unsetenv() function returns zero on success, or -1 on error, with errno set to indicate the cause of the error.
ERRORS
EINVAL name contained an ’=’ character.
CONFORMING TO
4.3BSD, POSIX.1-2001.
NOTES
Prior to glibc 2.2.2, unsetenv() was prototyped as returning void; more recent glibc versions follow the
POSIX.1-2001-compliant prototype shown in the SYNOPSIS.
BUGS
POSIX.1-2001 specifies that if name contains an ’=’ character, then setenv() should fail with the error EINVAL;
however, versions of glibc before 2.3.4 allowed an ’=’ sign in name.
SEE ALSO
clearenv(3), getenv(3), putenv(3), environ(7)
BSD 2004-05-09 SETENV(3)
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환경변수를 바꾸어 보려고 했더니, 프로그램 종료 후에는 그 환경변수를 사라지는 문제가 발생했다.
혹시나 해서 찾아 봤더니 원래 그렇다고 한다.
음.. 고정시키는 방법은 없을려나..
그리고, setenv() 사용시, 변수 치환은 되지 않는다.
예를 들어 A=str B=test 로 선언하고
setenv("C","$A $B",1) 라고 해도 C=str test 로 입력되지 않는다.
[링크 :
http://forum.falinux.com/zbxe/?document_srl=408397]
