projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 8404041d KM |
1 | .\" Copyright (c) 1983 Regents of the University of California. |
| 2 | .\" All rights reserved. The Berkeley software License Agreement | |
| 3 | .\" specifies the terms and conditions for redistribution. | |
| 4 | .\" | |
| c3457a1f | 5 | .\" @(#)environ.7 6.1 (Berkeley) %G% |
| 8404041d | 6 | .\" |
| c3457a1f | 7 | .TH ENVIRON 7 "" |
| 8404041d KM |
8 | .UC 5 |
| 9 | .SH NAME | |
| 10 | environ \- user environment | |
| 11 | .SH SYNOPSIS | |
| 12 | .B extern char **environ; | |
| 13 | .SH DESCRIPTION | |
| 14 | An array of strings called the `environment' is made available by | |
| 15 | .IR execve (2) | |
| 16 | when a process begins. By convention these strings have the form | |
| 17 | .RI ` name = value '. | |
| 18 | The following names are used by various commands: | |
| 19 | .TP "\w'TERMCAP 'u" | |
| 20 | PATH | |
| 21 | The sequence of directory prefixes that | |
| 22 | .I sh, time, | |
| 23 | .IR nice (1), | |
| 24 | etc., apply in searching for a file known by an incomplete path name. | |
| 25 | The prefixes are separated by `:'. | |
| 26 | .IR Login (1) | |
| 27 | sets PATH=:/usr/ucb:/bin:/usr/bin. | |
| 28 | .TP | |
| 29 | HOME | |
| 30 | A user's login directory, set by | |
| 31 | .IR login (1) | |
| 32 | from the password file | |
| 33 | .IR passwd (5). | |
| 34 | .TP | |
| 35 | TERM | |
| 36 | The kind of terminal for which output is to be prepared. | |
| 37 | This information is used by commands, such as | |
| 38 | .I nroff | |
| 39 | or | |
| 40 | .IR plot (1G), | |
| 41 | which may exploit special terminal capabilities. See | |
| 42 | .I /etc/termcap | |
| 43 | .RI ( termcap (5)) | |
| 44 | for a list of terminal types. | |
| 45 | .TP | |
| 46 | SHELL | |
| 47 | The file name of the users login shell. | |
| 48 | .TP | |
| 49 | TERMCAP | |
| 50 | The string describing the terminal in TERM, or the name of the termcap file, see | |
| 51 | .IR termcap (5), termcap (3X). | |
| 52 | .TP | |
| 53 | EXINIT | |
| 54 | A startup list of commands read by | |
| 55 | .IR ex (1), | |
| 56 | .IR edit (1), | |
| 57 | and | |
| 58 | .IR vi (1). | |
| 59 | .TP | |
| 60 | USER | |
| 61 | The login name of the user. | |
| 62 | .TP | |
| 63 | PRINTER | |
| 64 | The name of the default printer to be used by | |
| 65 | .IR lpr (1), | |
| 66 | .IR lpq (1), | |
| 67 | and | |
| 68 | .IR lprm (1). | |
| 69 | .PP | |
| 70 | Further names may be placed in the environment by the | |
| 71 | .I export | |
| 72 | command and `name=value' arguments in | |
| 73 | .IR sh (1), | |
| 74 | or by the | |
| 75 | .I setenv | |
| 76 | command if you use | |
| 77 | .IR csh (1). | |
| 78 | Arguments may also be placed in the environment at the point of an | |
| 79 | .IR execve (2). | |
| 80 | It is unwise to conflict with certain | |
| 81 | .IR sh (1) | |
| 82 | variables that are frequently exported by `.profile' files: | |
| 83 | MAIL, PS1, PS2, IFS. | |
| 84 | .SH SEE ALSO | |
| 85 | csh(1), | |
| 86 | ex(1), | |
| 87 | login(1), | |
| 88 | sh(1), | |
| 89 | execve(2), | |
| 90 | system(3), | |
| 91 | termcap(3X), | |
| 92 | termcap(5) |