environ(5)environ(5)NAMEenviron - 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 runtime environment.
HOME The name of the user's login directory, set by login(1) from
the password file (see passwd(4)).
LANG The program's locale. Locales consist of files that describe
the conventions appropriate to some nationality, culture, and
language. Generally, users determine which files are
selected by manipulating the environment variables described
below. For background, see setlocale(3C).
Locales are partitioned into categories LC_COLLATE, LC_CTYPE,
LC_MESSAGES, LC_MONETARY, LC_NUMERIC, and LC_TIME (see below
for what the categories control). Each category has a
corresponding environment variable that the user can set to
specify that category's locale:
LC_CTYPE=fr[ancais]
The LANG environment variable is searched if the environment
variable for a category is unset or empty:
LANG=fr
LC_COLLATE=de[utsche]
sets all the categories but LC_COLLATE to French. If LANG is
unset or empty, the default C locale is used.
LC_COLLATE specifies the collation order used. The
information for this category is stored in a
database created by the colltbl(1M) command.
This environment variable affects sort(1),
strcoll(3C), and strxfrm(3C).
LC_CTYPE specifies character classification, character
conversion, and widths of multibyte
characters. The information for this category
is stored in a database created by the
chrtbl(1M) or wchrtbl(1M) commands. The
default C locale uses the 7-bit US ASCII
character set. This environment variable
affects many commands and functions, among
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them, cat(1), ed(1), ls(1), vi(1), ctype(3C),
and mbchar(3C),
LC_MESSAGES specifies the message database used. A
command or application may have French and
German message databases, for example.
Message databases are created by the mkmsgs(1)
or gencat(1) commands. This environment
variable affects gettxt(1), srchtxt(1),
catgets(3C), and gettxt(3C), and every command
that generates locale-specific output
messages.
LC_MONETARY specifies the monetary symbols and delimiters
used. The information for this category is
stored in a database created by the montbl(1M)
command. This environment variable affects
localeconv(3C).
LC_NUMERIC specifies the decimal and thousands
delimiters. The information for this category
is stored in a database created by the
chrtbl(1M) or wchrtbl(1M) commands. The
default C locale uses a period (.) as the
decimal delimiter and no thousands delimiter.
This environment variable affects
localeconv(3C), printf(3S), scanf(3S), and
strtod(3C).
LC_TIME specifies date and time formats. The
information for this category is stored in a
database specified in strftime(4). The
default C locale uses US date and time
formats. This environment variable affects
many commands and functions, among them,
at(1), calendar(1), date(1), getdate(3C), and
strftime(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 UNIX System V
networking libraries (see intro(3N)) 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
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network contained in that network's entry. /etc/netconfig is
maintained by the system administrator. The library routines
described in getnetpath(3C) access the NETPATH environment
variable.
NOMSGLABEL Used to turn off the label portion of pfmt message component.
(see pfmt(3C)).
NOMSGSEVERITY
Used to turn off the severity portion of pfmt message
component. (see pfmt(3C)).
SEV_LEVEL Defines severity levels and associates and prints strings
with them in standard format error messages (see
addseverity(3C), fmtmsg(1), and fmtmsg(3C)).
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:
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_______________________________________________________________________________
%N The value of the name parameter passed to catopen.
%L The value of LANG environment variable if oflag is 0.
The value of LC_MESSAGES category if oflag is NL_CAT_LOCALE.
%l The language element from LANG environment variable if oflag is 0.
The language element from LC_MESSAGES category if oflag is
NL_CAT_LOCALE.
%t The territory element from LANG environment variable if oflag is 0.
The territory element from LC_MESSAGES category if oflag is
NL_CAT_LOCALE.
%c The codeset element from LANG environment variable if oflag is 0.
The codeset element from LC_MESSAGES category if oflag is
NL_CAT_LOCALE.
%% A single % character.
______________________________________________________________________________
|
|
where oflag is a second argument of catopen.
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/name4
def.cat (if oflag is set to 0).
LD_LIBRARY_PATH
Can override the normal library search paths
(/lib:/lib/cmplrs/cc:/usr/lib:/usr/lib/cmplrs/cc) (For more
detail, see rld(1).)
_RLD_ARGS Can specify runtime linker options. (For more detail, see
rld(1).)
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PATH The sequence of directory prefixes that sh(1), time(1),
nice(1), nohup(1), and so on apply in searching for a file
known by an incomplete pathname. The prefixes are separated
by colons (:). login(1) sets
PATH=:/usr/sbin:/usr/bsd:/sbin:/usr/bin:/usr/bin/X11. (For
more detail, see login(1) and sh(1).)
SHELL When the shell is invoked, it scans the environment for this
name. If it is found and rsh is the filename part of its
value, the shell becomes a restricted shell. The value of
this variable should be specified with an absolute pathname.
The variable is used by make(1), ksh(1), sh(1), and vi(1),
among other commands.
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. In
this implementation, it is the name (not including the
starting colon (:) character) of a zoneinfo file relative to
/usr/lib/locale/TZ/. For sh(1) users, the following example
sets the TZ variable to US Central timezone:
TZ=:US/Central
and the zoneinfo file /usr/lib/locale/TZ/US/Central will be used by the
time functions mentioned above (See zic(1M) for more information on
zoneinfo files). 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 lowercase 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:
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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
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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For example, the most complete setting for New Jersey in
1986 could be
EST5:00:00EDT4:00:00,116/2:00:00,298/2:00:00
or simply
EST5EDT
In the longer version of the New Jersey example of TZ,
EST is the abbreviation for the main time zone, 5:00:00
is the difference, in hours, minutes, and seconds
between GMT and the main time zone, EDT is the
abbreviation for the alternate time zone, 4:00:00 is the
difference, in hours, minutes, and seconds between GMT
and the alternate time zone, 116 is the number of the
day of the year (Julian day) when the alternate time
zone will take effect, 2:00:00 is the number of hours,
minutes, and seconds past midnight when the alternate
time zone will take effect, 298 is the number of the day
of the year when the alternate time zone will end, and
2:00:00 is the number of hours, minutes, and seconds
past midnight when the alternate time zone will end.
Timezone specifications under the IRIX 4 operating
system used a ";" to separate the dst field from the
start field. In conformance with the X/Open XPG4
standard, this is no longer legal, and a "," must be
used in place of the ";".
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 ALSOcat(1), chrtbl(1M), colltbl(1M), date(1), ed(1), fmtmsg(1), gencat(1),
gettxt(1), login(1), ls(1), mkmsgs(1), mm(1), montbl(1M), nice(1),
nohup(1), sh(1), sort(1), srchtxt(1), time(1), vi(1), wchrtbl(1M),
zdump(1M), zic(1M), exec(2), addseverity(3C), catgets(3C), catopen(3C),
ctime(3C), ctype(3C), fmtmsg(3C), getdate(3C), getnetpath(3N),
gettxt(3C), localeconv(3C), mbchar(3C), mktime(3C), printf(3S),
scanf(3S), setlocale(3C), strcoll(3C), strftime(3C), strtod(3C),
strxfrm(3C), netconfig(4), passwd(4), profile(4), strftime(4),
strftime(4), timezone(4)
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