ENVIRON(5-SVR4) RISC/os Reference Manual ENVIRON(5-SVR4)
NAME
environ - user environment
DESCRIPTION
When a process begins execution, exec routines make avail-
able 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 applica-
tions 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 informa-
tion 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(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 conven-
tions by setting the appropriate environment vari-
ables.
The following environment variables are supported
to correspond with each category of setlocale(3C):
LC_COLLATE This category specifies the colla-
tion sequence being used. The
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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 conver-
sion, and widths of multibyte char-
acters. 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 environ-
ment variable is used by ctype(3C),
mbchar(3C), and many commands; for
example: 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 appli-
cation may have one message data-
base with French messages, and
another database with German mes-
sages. Message databases are
created by the mkmsgs(1M) command.
This environment variable is used
by exstr(1), gettxt(1), gettxt(3C),
and srchtxt(1).
LC_MONETARY This category specifies the mone-
tary symbols and delimiters used
for a particular locale. The infor-
mation 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 environ-
ment variable is used by
localeconv(3C), printf(3C), and
strtod(3C).
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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 func-
tions; for example: at(1), calen-
dar(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)].
SEV_LEVEL Define severity levels and associate and print
strings with them in standard format error mes-
sages [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. Net-
work 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.
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Substitution fields consist of a % symbol, fol-
lowed 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.___________|
An empty string is substituted if the specified
value is not currently defined. The separators
``_'' and ``.'' are not included in %t and %c sub-
stitutions.
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 search-
ing 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]]]
std and dst
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Three or more bytes that are the designa-
tion 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 Univer-
sal 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 follow-
ing 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.
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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.
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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.
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), netcon-
fig(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.
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