Manual page for environ(5)
environ - user environment
DESCRIPTION
When a process begins execution,
exec
routines make available an array of strings called the
environment; see
exec.2
By convention, these strings have the form variable=value,
for example, PATH=/sbin:/usr/sbin.
These environmental variables provide a way to make
information about a program's environment available to programs.
A name may be placed in the environment by
the
export
command and
name=value
arguments in
sh.1
or by
exec.2
It is unwise to conflict with
certain shell variables that are frequently exported by
.profile
files:
MAIL,
PS1,
PS2,
IFS;
see
profile.4
The following environmental variables can be used by
applications and are expected to be set in the target run-time environment.
- HOME
-
The name of the user's login directory, set by
login.1
from the password file; see
passwd.4
- LANG
-
The string used to specify internationalization information that
allows users to work with different national conventions.
The
setlocale.3c
function
checks the
LANG
environment variable
when it is called with "" as the
locale
argument.
LANG
is used as the default locale if the corresponding
environment variable for a particular category is unset or null.
If, however,
LC_ALL
is set to a valid, non-empty value, its contents are used
to override both the
LANG
and the other
LC_*
variables.
For example, when
setlocale()
is invoked as
setlocale(LC_CTYPE, ""),
setlocale()
will query the
LC_CTYPE
environment variable first to see if it is set and non-null.
If
LC_CTYPE
is not set or null,
then
setlocale()
will check the
LANG
environment variable to see if it is set and non-null.
If both
LANG
and
LC_CTYPE
are unset or
NULL,
the default "C" locale will be used to set the
LC_CTYPE
category.
Most commands will invoke
-
setlocale(LC_ALL, "")
prior to any other processing.
This allows the command to be used with different national conventions
by setting the appropriate environment variables.
The following environment variables
correspond to each category of
setlocale.3c
-
- LC_ALL
-
If set to a valid, non-empty string value, override the values of
LANG
and all the other
LC_*
variables.
- LC_COLLATE
-
This category specifies the character collation sequence being used.
The information corresponding to this category is stored in a database
created by the
colltbl.1m
command.
This environment variable affects
strcoll.3c
and
strxfrm.3c
- LC_CTYPE
-
This category specifies character classification, character conversion,
and widths of multibyte characters.
When
LC_CTYPE
is set to a valid value, the calling utility can display and handle
text and file names containing valid characters for that locale;
Extended Unix Code (EUC) characters where any individual character can
be 1, 2, or 3 bytes wide; and EUC characters of 1, 2, or 3 column widths.
The default "C" locale corresponds to the 7-bit
ASCII
character set; only characters from ISO 8859-1 are valid.
The information corresponding to this category is stored
in a database created by the
chrtbl.1m
command.
This environment variable is used by
ctype.3c
mbchar.3c
and many commands,
such as
cat.1
ed.1
ls.1
and
vi.1
- LC_MESSAGES
-
This category specifies the language of the message database being used.
For example, an application may have one message database
with French messages, and another database with German messages.
Message databases are created by the
mkmsgs.1
command.
This environment variable is used by
exstr.1
gettxt.1
srchtxt.1
gettxt.3c
and
gettext.3i
- LC_MONETARY
-
This category specifies the monetary symbols and delimiters used for a particular
locale.
The information corresponding to this category is stored in a database created
by the
montbl.1m
command.
This environment variable is used by
localeconv.3c
- LC_NUMERIC
-
This category specifies the decimal and thousands delimiters.
The information corresponding to this category is stored in a database
created by the
chrtbl.1m
command.
The default
C
locale corresponds to "." as the decimal delimiter and no thousands delimiter.
This environment variable is used by
localeconv.3c
printf.3s
and
strtod.3c
- LC_TIME
-
This category specifies date and time formats.
The information corresponding to this category is stored
in a database specified in
strftime.4
The default
C
locale corresponds to U.S. date and time formats.
This environment variable is used by
many commands and functions;
for example:
at.1
calendar.1
date.1
strftime.3c
and
getdate.3c
- MSGVERB
-
Controls which standard format message components
fmtmsg selects when messages are displayed to
stderr;
see
fmtmsg.1
and
fmtmsg.3c
- NETPATH
-
A colon-separated list of network identifiers.
A network identifier is a character string used by the
Network Selection
component of the system to provide application-specific default
network search paths.
A network identifier must consist of non-NULL
characters and must have a length of at least 1.
No maximum length is specified.
Network identifiers are normally chosen
by the system administrator.
A network identifier is also the first field in
any
/etc/netconfig
file entry.
NETPATH
thus provides a link into the
/etc/netconfig
file and the information about a network contained in that network's entry.
/etc/netconfig
is maintained by the system administrator.
The library routines described in
getnetpath.3n
access the
NETPATH
environment variable.
- NLSPATH
-
Contains a sequence of templates which
catopen.3c
and
gettext.3i
use when attempting to locate message catalogs.
Each template consists of
an optional prefix,
one or more substitution fields,
a filename and an optional suffix.
For example:
NLSPATH="/system/nlslib/%N.cat"
defines that
catopen()
should look for all message catalogs in the
directory
/system/nlslib,
where the catalog name should be constructed from the
name
parameter passed to
catopen(),
%N,
with the suffix .cat.
Substitution fields consist of a
%
symbol, followed by a single-letter keyword.
The following keywords are currently defined:
+-----------------------------------------------------+
|%N The value of the name parameter passed to |
| catopen(). |
|%L The value of LANG or LC_MESSAGES. |
|%l The language element from LANG or LC_MESSAGES. |
|%t The territory element from LANG or LC_MESSAGES. |
|%c The codeset element from LANG or LC_MESSAGES. |
|%% A single % character. |
+-----------------------------------------------------+
An empty string is substituted if the specified value is not
currently defined.
The separators ``_'' and ``.'' are not included in
%t and %c
substitutions.
Templates defined in
NLSPATH
are separated by colons (:).
A leading colon or two adjacent colons (::) is equivalent to
specifying %N.
For example:
NLSPATH=":%N.cat:/nlslib/%L/%N.cat"
indicates to
catopen()
that it should look for the requested message catalog in
name,
name.cat
and
/nlslib/$LANG/name.cat.
For
gettext(),
%N
automatically maps to "messages".
If
NLSPATH
is unset or
NULL,
catopen()
and
gettext()
call
setlocale.3c
which checks
LANG
and the
LC_*
variables to locate the message catalogs.
NLSPATH
will normally be set up on a system wide basis (in
/etc/profile)
and thus makes the location and naming
conventions associated with message catalogs transparent
to both programs and users.
- PATH
-
The sequence of directory prefixes that
sh.1
time.1
nice.1
nohup.1
and other utilities
apply in searching for a file known by an incomplete path name.
The prefixes are separated by colons
(:).
login.1
sets
PATH=/usr/bin.
For more detail, see
sh.1
- SEV_LEVEL
-
Define severity levels and associate and print strings
with them in standard format error messages; see
addseverity.3c
fmtmsg.1
and
fmtmsg.3c
- TERM
-
The kind of terminal for which output is to be prepared.
This information is used by commands, such as
vi.1
which may exploit special capabilities of that terminal.
- TZ
-
Timezone information.
The contents of this environment variable
are used by the functions
ctime.3c
localtime.3c
strftime.3c
and
mktime.3c
to override the default timezone.
If
TZ
is not in the following form, it designates a path to a
timezone
database file relative to
/usr/share/lib/zoneinfo/,
ignoring the first character if it is a colon
(:);
otherwise,
TZ
has the form:
stdoffset[dst[offset],[start[/time],end[/time]]]
-
- std and dst
-
Three or more bytes that are the designation for the standard
(std)
and daylight savings time
(dst)
timezones. Only
std
is required. If
dst
is missing, then daylight savings time does not apply in this locale.
Upper- and lower-case letters are allowed. Any characters
except a leading colon (:), digits, a comma (,), a minus
(-)
or a plus (+) are allowed.
- offset
-
Indicates the value one must add to the local time to arrive at
Coordinated Universal Time. The offset has the form:
hh[:mm[:ss]]
The minutes
(mm)
and seconds
(ss)
are optional. The hour
(hh)
is required and may be a single digit. The
offset
following
std
is required. If no
offset
follows
dst ,
daylight savings time is assumed to be one hour ahead of standard time.
One or more digits may be used; the value is always
interpreted as a decimal number. The hour must be between 0
and 24, and the minutes (and seconds) if present between 0 and
59. Out of range values may cause unpredictable behavior. If preceded
by a ``-'', the timezone is east of the Prime Meridian;
otherwise it is west (which may be indicated by an optional
preceding ``+'' sign).
- start/time,end/time
-
Indicate when to change to and back from daylight savings time, where
start/time
describes when the change from standard time to daylight savings time occurs, and
end/time
describes when the change back happens. Each
time
field describes when, in current local time, the change is made.
The formats of
start
and
end
are one of the following:
-
- Jn
-
The Julian day
n
(1 <=
n
<= 365).
Leap days are not counted. That is, in all years, February 28 is
day 59 and March 1 is day 60. It is impossible to refer to the occasional
February 29.
- n
-
The zero-based Julian day
(0 <=
n
<= 365).
Leap days are counted,
and it is possible to refer to
February 29.
- Mm.n.d
-
The
dth
day,
(0 <=
d
<= 6) of week
n
of month
m
of the year
(1 <=
n
<= 5, 1 <=
m
<= 12), where week 5 means ``the last
d-day
in month
m''
which may occur in either the fourth or the fifth week).
Week 1 is the first week in which the
dth
day occurs.
Day zero is Sunday.
Implementation specific defaults are used for
start
and
end
if these optional fields are not given.
The
time
has the same format as
offset
except that no leading sign (``-'' or ``+'') is allowed.
The default, if
time
is not given is 02:00:00.
SEE ALSO
cat.1
date.1
ed.1
fmtmsg.1
login.1
ls.1
mkmsgs.1
nice.1
nohup.1
sh.1
sort.1
time.1
vi.1
chrtbl.1m
colltbl.1m
montbl.1m
exec.2
addseverity.3c
catopen.3c
ctime.3c
ctype.3c
fmtmsg.3c
getdate.3c
getnetpath.3n
gettext.3i
gettxt.3c
localeconv.3c
mbchar.3c
mktime.3c
printf.3s
setlocale.3c
strcoll.3c
strftime.3c
strtod.3c
strxfrm.3c
netconfig.4
passwd.4
profile.4
strftime.4
TIMEZONE.4
Created by unroff & hp-tools.
© somebody (See intro for details). All Rights Reserved.
Last modified 11/5/97