xref: /csrg-svn/share/man/man7/environ.7 (revision 66981)
161609Sbostic.\" Copyright (c) 1983, 1990, 1993
261609Sbostic.\"	The Regents of the University of California.  All rights reserved.
320969Smckusick.\"
450441Scael.\" %sccs.include.redist.roff%
520969Smckusick.\"
6*66981Sbostic.\"	@(#)environ.7	8.3 (Berkeley) 04/19/94
743687Scael.\"
843687Scael.Dd
943687Scael.Dt ENVIRON 7
1043687Scael.Os BSD 4.2
1143687Scael.Sh NAME
1243687Scael.Nm environ
1343687Scael.Nd user environment
1443687Scael.Sh SYNOPSIS
1543687Scael.Ar extern char **environ ;
1643687Scael.Sh DESCRIPTION
1732394SjakAn array of strings called the
1843687Scael.Ar environment
1932394Sjakis made available by
2043687Scael.Xr execve  2
2120969Smckusickwhen a process begins.  By convention these strings have the form
2243687Scael.Dq Ar name=value .
2343687ScaelThe following names are used by various commands:
2452777Sbostic.Bl -tag -width BLOCKSIZE
2552777Sbostic.It Ev BLOCKSIZE
2652777SbosticThe size of the block units used by several commands, most notably
2752777Sbostic.Xr df 1 ,
2852777Sbostic.Xr du 1
2952777Sbosticand
3052777Sbostic.Xr ls 1 .
3152777SbosticBLOCKSIZE may be specified in units of a byte by specifying a number,
3252777Sbosticin units of a kilobyte by specifying a number followed by ``K'' or
3352777Sbostic``k'', in units of a megabyte by specifying a number followed by ``M''
3452777Sbosticor ``m'' and in units of a gigabyte by specifying a number followed
3552777Sbosticby ``G'' or ``g''.
3652777SbosticSizes less than 512 bytes or greater than a gigabyte are ignored.
3750441Scael.It Ev EXINIT
3832394SjakA startup list of commands read by
3943687Scael.Xr ex  1  ,
4043687Scael.Xr edit  1 ,
4132394Sjakand
4243687Scael.Xr vi  1  .
4350441Scael.It Ev HOME
4420969SmckusickA user's login directory, set by
4543687Scael.Xr login  1
4620969Smckusickfrom the password file
4743687Scael.Xr passwd  5  .
4850441Scael.It Ev PATH
4932394SjakThe sequence of directories, separated by colons, searched by
5043687Scael.Xr csh  1  ,
5143687Scael.Xr sh  1 ,
5243687Scael.Xr system  3  ,
5343687Scael.Xr execvp  3 ,
5432395Sbosticetc, when looking for an executable file.
5532395SbosticPATH is set to ``:/usr/ucb:/bin:/usr/bin'' initially by
5643687Scael.Xr login  1  .
5750441Scael.It Ev PRINTER
5832394SjakThe name of the default printer to be used by
5943687Scael.Xr lpr  1  ,
6043687Scael.Xr lpq  1 ,
6132394Sjakand
6243687Scael.Xr lprm  1  .
6350441Scael.It Ev SHELL
6432394SjakThe full pathname of the user's login shell.
6550441Scael.It Ev TERM
6620969SmckusickThe kind of terminal for which output is to be prepared.
6720969SmckusickThis information is used by commands, such as
6843687Scael.Xr nroff  1
6920969Smckusickor
7043687Scael.Xr plot 1
7120969Smckusickwhich may exploit special terminal capabilities.  See
7243687Scael.Pa /usr/share/misc/termcap
73*66981Sbostic.Pq Xr termcap 5
7420969Smckusickfor a list of terminal types.
7550441Scael.It Ev TERMCAP
7632394SjakThe string describing the terminal in TERM, or, if
7732394Sjakit begins with a '/', the name of the termcap file.
7843687ScaelSee
7943687Scael.Ev TERMPATH
8043687Scaelbelow,
8143687Scael.Xr termcap  5  ,
8220969Smckusickand
8343687Scael.Xr termcap  .
8450441Scael.It Ev TERMPATH
8532394SjakA sequence of pathnames of termcap files, separated by colons or spaces,
8632395Sbosticwhich are searched for terminal descriptions in the order listed.  Having
8743687Scaelno
8843687Scael.Ev TERMPATH
8943687Scaelis equivalent to a
9043687Scael.Ev TERMPATH
9143687Scaelof
9243687Scael.Dq Pa $HOME/.termcap:/etc/termcap .
9343687Scael.Ev TERMPATH
9443687Scaelis ignored if
9543687Scael.Ev TERMCAP
9643687Scaelcontains a full pathname.
9756676Sbostic.It Ev TMPDIR
9856676SbosticThe directory in which to store temporary files.
9956676SbosticMost applications use either
10056676Sbostic.Dq /tmp
10156676Sbosticor
10256676Sbostic.Dq /var/tmp .
10356676SbosticSetting this variable will make them use another directory.
10464910Sbostic.It Ev TZ
10564910SbosticThe timezone to use when displaying dates.
10664910SbosticThe normal format is a pathname relative to
10764910Sbostic.Dq /usr/share/zoneinfo .
10864910SbosticFor example, the command
10964910Sbostic.Dq env TZ=US/Pacific date
11064910Sbosticdisplays the current time in California.
11164910SbosticSee
11264910Sbostic.Xr tzset 3
11364910Sbosticfor more information.
11450441Scael.It Ev USER
11520969SmckusickThe login name of the user.
11650441Scael.El
11743687Scael.Pp
11820969SmckusickFurther names may be placed in the environment by the
11943687Scael.Xr export
12032394Sjakcommand and
12143687Scael.Ar name=value
12232394Sjakarguments in
12343687Scael.Xr sh  1  ,
12420969Smckusickor by the
12543687Scael.Xr setenv
12620969Smckusickcommand if you use
12743687Scael.Xr csh  1  .
12843687ScaelIt is unwise to change certain
12943687Scael.Xr sh  1
13032394Sjakvariables that are frequently exported by
13143687Scael.Pa .profile
13243687Scaelfiles, such as
13343687Scael.Ev MAIL ,
13443687Scael.Ev PS1 ,
13543687Scael.Ev PS2 ,
13643687Scaeland
13743687Scael.Ev IFS ,
13832394Sjakunless you know what you are doing.
13943687Scael.Sh SEE ALSO
14043687Scael.Xr csh 1 ,
14143687Scael.Xr ex 1 ,
14243687Scael.Xr login 1 ,
14343687Scael.Xr sh 1 ,
14443687Scael.Xr execve 2 ,
14543687Scael.Xr execle 3 ,
14643687Scael.Xr system 3 ,
14743687Scael.Xr termcap 3 ,
14843687Scael.Xr termcap 5
14943687Scael.Sh HISTORY
15050441ScaelThe
15150441Scael.Nm environ
15250441Scaelmanual page appeared in
15350441Scael.Bx 4.2 .
154