environ(5) environ(5)
NAME
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.
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 localization information that
allows users to work with different national conventions.
The setlocale(3C) function looks for 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.
For example, when setlocale() is invoked as
setlocale(LCCTYPE, ""),
setlocale() will query the LCCTYPE environment variable
first to see if it is set and non-null. If LCCTYPE 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 LCCTYPE are unset or null, the default
C locale will be used to set the LCCTYPE category.
Most commands will invoke
setlocale(LCALL, "")
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 are supported to
correspond with each category of setlocale(3C):
LCCOLLATE This category specifies the 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).
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LCCTYPE This category specifies character
classification, character conversion, and
widths of multibyte characters. The
information corresponding to this category
is stored in a database created by the
chrtbl(1M) command. The default C locale
corresponds to the 7-bit ASCII character
set. This environment variable is used by
ctype(3C), mbchar(3C), and many commands;
for example: cat(1), ed(1), ls(1), and
vi(1).
LCMESSAGES 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(1M) command. This environment
variable is used by exstr(1), gettxt(1),
gettxt(3C), and srchtxt(1).
LCMONETARY 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).
LCNUMERIC 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(3C), and strtod(3C).
LCTIME 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).
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MSGVERB Controls which standard format message components fmtmsg
selects when messages are displayed to stderr [see
fmtmsg(1) and fmtmsg(3C)].
SEVLEVEL Define severity levels and associate and print strings
with them in standard format error messages [see
addseverity(3C), 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) uses
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. |
| %l The language element from LANG. |
| %t The territory element from LANG.|
| %c The codeset element from LANG. |
| %% A single % character. |
|______________________________________|
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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.
PATH The sequence of directory prefixes that sh(1), time(1),
nice(1), nohup(1), etc., 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).)
TERM The kind of terminal for which output is to be prepared.
This information is used by commands, such as mm(1) or
vi(1), which may exploit special capabilities of that
terminal.
TZ Time zone information.
The contents of the environment variable named TZ are
used by the functions ctime(3C), localtime() (see
ctime(3C)), strftime(3C) and mktime(3C) to override the
default timezone. If the first character of TZ is a
colon (:), the behavior is implementation defined,
otherwise TZ has the form:
stdoffset[dst[offset],[start[/time],end[/time]]]
Where:
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]]
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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
Indicates 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.
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Further names 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)).
SEE ALSO
chrtbl(1M), colltbl(1M), mkmsgs(1M), montbl(1M), netconfig(4),
strftime(4), passwd(4), profile(4) in the System Administrator's
Reference Manual.
exec(2), addseverity(3C), catopen(3C), ctime(3C), ctype(3C),
fmtmsg(3C), getdate(3C), gettxt(3C), localeconv(3C), mbchar(3C),
mktime(3C), printf(3C), strcoll(3C), strftime(3C), strtod(3C),
strxfrm(3C), strftime(4), timezone(4).
cat(1), date(1), ed(1), fmtmsg(1), ls(1), login(1), nice(1),
nohup(1), sh(1), sort(1), time(1), vi(1) in the User's Reference
Manual.
getnetpath(3N), in the Programmer's Guide: Networking Interfaces.
mm(1) in the DOCUMENTER'S WORKBENCH Software Technical Discussion and
Reference Manual.
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