CLEARENV(3) Library Functions Manual CLEARENV(3)NAME
clearenv - clear the environment
SYNOPSIS
#include <stdlib.h>
int clearenv(void);
DESCRIPTION
The clearenv() function clears the environment of all name-value pairs and sets the value of the external variable environ to NULL.
RETURN VALUE
The clearenv() function returns zero on success, and a non-zero value on failure.
AVAILABILITY
Not in libc4, libc5. In glibc since glibc 2.0.
CONFORMING TO
Various Unix variants (DGUX, HPUX, QNX, ...). POSIX.9 (bindings for FORTRAN77). POSIX.1-1996 did not accept clearenv() and putenv(), but
changed its mind and scheduled these functions for some later issue of this standard (cf. B.4.6.1). However, SUSv3 only adds putenv(), and
rejected clearenv().
NOTES
Used in security-conscious applications. If it is unavailable the assignment
environ = NULL;
will probably do.
The DGUX and Tru64 manpages write: If environ has been modified by anything other than the putenv(), getenv(), or clearenv() functions,
then clearenv() will return an error and the process environment will remain unchanged.
SEE ALSO getenv(3), putenv(3), setenv(3), unsetenv(3), environ(5)Linux Programmer's Manual 2001-10-17 CLEARENV(3)
Check Out this Related Man Page
CLEARENV(3) Linux Programmer's Manual CLEARENV(3)NAME
clearenv - clear the environment
SYNOPSIS
#include <stdlib.h>
int clearenv(void);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
clearenv(): _SVID_SOURCE || _BSD_SOURCE
DESCRIPTION
The clearenv() function clears the environment of all name-value pairs and sets the value of the external variable environ to NULL.
RETURN VALUE
The clearenv() function returns zero on success, and a nonzero value on failure.
VERSIONS
Not in libc4, libc5. In glibc since glibc 2.0.
CONFORMING TO
Various UNIX variants (DG/UX, HP-UX, QNX, ...). POSIX.9 (bindings for FORTRAN77). POSIX.1-1996 did not accept clearenv() and putenv(3),
but changed its mind and scheduled these functions for some later issue of this standard (cf. B.4.6.1). However, POSIX.1-2001 only adds
putenv(3), and rejected clearenv().
NOTES
Used in security-conscious applications. If it is unavailable the assignment
environ = NULL;
will probably do.
The DG/UX and Tru64 man pages write: If environ has been modified by anything other than the putenv(3), getenv(3), or clearenv() functions,
then clearenv() will return an error and the process environment will remain unchanged.
SEE ALSO getenv(3), putenv(3), setenv(3), unsetenv(3), environ(7)COLOPHON
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2010-10-04 CLEARENV(3)
Hi All,
Can anybody tell what is the reason
when I type df . the result shows as below
Filesystem 1024-blocks Used Available Capacity Mounted on
data3_domain#data3 35556784 31222753 3809472 90% /data3
so, in /data3 still 10% available to... (11 Replies)
Hello.....
I installed netscape 4.0 for HPUX-11 but i don`t know to configure that ,
Maybe samone know how i can gate
the procedure to installing NETSCAPE for HPUX-11 for user or server.
Thank you in advance !!!! (3 Replies)
HI all,
Any one have the sample C code which uses the Sharedmemory concept
in HPUX, AS400, OS390 .please send the links.
Thanks in Advance
Chinna (0 Replies)
HI ALL,
I am new tp HPUX and i am looking for command that will retive me the following information on HPUX:
Chassis Name & Serial Number:
Monitor
Name
BIOS
Name
EthernetPort
Name
IPEndpoint
Name
PointingDevice
Name
Keyboard
NetworkPrinter
Name
LocalPrinter (5 Replies)
Hi Guys,
This site is great for Unix Gurus and Newbies (like me) alike!
Anyway, anybody had experience with an OLD QNX? ver. 4.238? I know it's old, that is why we are migrating the data but vendors can't connect to it. Probably because of the incorrect gateway defined in it.
Anyway to... (4 Replies)
Hi all,
Having a bit of fun with a very old DGUX box and need help if possible.
Up untill we installed a new UPS today the DGUX has been sat in a corner happily humming away.
It has been rebooted about 3 times in the last six months that i am aware of.
I did the usual "shutdown -y" to... (4 Replies)
Old DG box Aviion PentiumPro running R4.20Mu06 being used to try to recreate Ingres db from backup tapes so machine has not been operational before and some of original files in /etc may have ben overwritten
Unable to get NIC working
Any pointers on how to go about configuring NIC :rolleyes: (0 Replies)
Hi Guys,
Hopefully someone would be able to help me out. Basically I have an HPUX 11.11i system which is backed up by Data Protector 4.5. Every so often the vdba process hangs and chews up 100% of one of the systems CPU resources. As our monitoring tool can only monitor on a per system basis... (3 Replies)
I am new for HPUX OS and want to pursue my career in HPUX Administration.
I could not able to get following information from HP.com site, that why I need an assistance to know that - can I install HPUX 11i V3 OS on old HP B2000 & B1000 workstations (these workstation are 4 to 5 year old) or not,... (5 Replies)
Hello all, very much a Unix newbie.
My company has an old DG/UX system we use for customer data. I need to archive some data to clear some space, so I wanted to be able to list items in each directory by size, to grab some "low hanging" fruit to give me some breathing room as the system is... (0 Replies)
OK HPUX masters I need help. I have a HPUX 11.23 server that I am using as a Ignite server that services two HPUX services for backups only. The other day I noticed that our Make Net Recoveries were failing. Upon attempting to login to the server SSH and could not I then tried to ping and could... (6 Replies)