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diff --git a/man1/intro.1 b/man1/intro.1 new file mode 100644 index 0000000..06905e1 --- /dev/null +++ b/man1/intro.1 @@ -0,0 +1,305 @@ +.\" Copyright (c) 2002 Andries Brouwer <aeb@cwi.nl> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.TH intro 1 2023-05-03 "Linux man-pages 6.05.01" +.SH NAME +intro \- introduction to user commands +.SH DESCRIPTION +Section 1 of the manual describes user commands and tools, +for example, file manipulation tools, shells, compilers, +web browsers, file and image viewers and editors, and so on. +.SH NOTES +Linux is a flavor of UNIX, and as a first approximation +all user commands under UNIX work precisely the same under +Linux (and FreeBSD and lots of other UNIX-like systems). +.PP +Under Linux, there are GUIs (graphical user interfaces), where you +can point and click and drag, and hopefully get work done without +first reading lots of documentation. +The traditional UNIX environment +is a CLI (command line interface), where you type commands to +tell the computer what to do. +That is faster and more powerful, +but requires finding out what the commands are. +Below a bare minimum, to get started. +.SS Login +In order to start working, you probably first have to open a session by +giving your username and password. +The program +.BR login (1) +now starts a +.I shell +(command interpreter) for you. +In case of a graphical login, you get a screen with menus or icons +and a mouse click will start a shell in a window. +See also +.BR xterm (1). +.SS The shell +One types commands to the +.IR shell , +the command interpreter. +It is not built-in, but is just a program +and you can change your shell. +Everybody has their own favorite one. +The standard one is called +.IR sh . +See also +.BR ash (1), +.BR bash (1), +.BR chsh (1), +.BR csh (1), +.BR dash (1), +.BR ksh (1), +.BR zsh (1). +.PP +A session might go like: +.PP +.in +4n +.EX +.RB "knuth login: " aeb +.RB "Password: " ******** +.RB "$ " date +Tue Aug 6 23:50:44 CEST 2002 +.RB "$ " cal + August 2002 +Su Mo Tu We Th Fr Sa + 1 2 3 + 4 5 6 7 8 9 10 +11 12 13 14 15 16 17 +18 19 20 21 22 23 24 +25 26 27 28 29 30 31 +\& +.RB "$ " ls +bin tel +.RB "$ " "ls \-l" +total 2 +drwxrwxr\-x 2 aeb 1024 Aug 6 23:51 bin +\-rw\-rw\-r\-\- 1 aeb 37 Aug 6 23:52 tel +.RB "$ " "cat tel" +maja 0501\-1136285 +peter 0136\-7399214 +.RB "$ " "cp tel tel2" +.RB "$ " "ls \-l" +total 3 +drwxr\-xr\-x 2 aeb 1024 Aug 6 23:51 bin +\-rw\-r\-\-r\-\- 1 aeb 37 Aug 6 23:52 tel +\-rw\-r\-\-r\-\- 1 aeb 37 Aug 6 23:53 tel2 +.RB "$ " "mv tel tel1" +.RB "$ " "ls \-l" +total 3 +drwxr\-xr\-x 2 aeb 1024 Aug 6 23:51 bin +\-rw\-r\-\-r\-\- 1 aeb 37 Aug 6 23:52 tel1 +\-rw\-r\-\-r\-\- 1 aeb 37 Aug 6 23:53 tel2 +.RB "$ " "diff tel1 tel2" +.RB "$ " "rm tel1" +.RB "$ " "grep maja tel2" +maja 0501\-1136285 +$ +.EE +.in +.PP +Here typing Control-D ended the session. +.PP +The +.B $ +here was the command prompt\[em]it is the shell's way of indicating +that it is ready for the next command. +The prompt can be customized +in lots of ways, and one might include stuff like username, +machine name, current directory, time, and so on. +An assignment PS1="What next, master? " +would change the prompt as indicated. +.PP +We see that there are commands +.I date +(that gives date and time), and +.I cal +(that gives a calendar). +.PP +The command +.I ls +lists the contents of the current directory\[em]it tells you what +files you have. +With a +.I \-l +option it gives a long listing, +that includes the owner and size and date of the file, and the +permissions people have for reading and/or changing the file. +For example, the file "tel" here is 37 bytes long, owned by aeb +and the owner can read and write it, others can only read it. +Owner and permissions can be changed by the commands +.I chown +and +.IR chmod . +.PP +The command +.I cat +will show the contents of a file. +(The name is from "concatenate and print": all files given as +parameters are concatenated and sent to "standard output" +(see +.BR stdout (3)), +here +the terminal screen.) +.PP +The command +.I cp +(from "copy") will copy a file. +.PP +The command +.I mv +(from "move"), on the other hand, only renames it. +.PP +The command +.I diff +lists the differences between two files. +Here there was no output because there were no differences. +.PP +The command +.I rm +(from "remove") deletes the file, and be careful! it is gone. +No wastepaper basket or anything. +Deleted means lost. +.PP +The command +.I grep +(from "g/re/p") finds occurrences of a string in one or more files. +Here it finds Maja's telephone number. +.SS Pathnames and the current directory +Files live in a large tree, the file hierarchy. +Each has a +.I "pathname" +describing the path from the root of the tree (which is called +.IR / ) +to the file. +For example, such a full pathname might be +.IR /home/aeb/tel . +Always using full pathnames would be inconvenient, and the name +of a file in the current directory may be abbreviated by giving +only the last component. +That is why +.I /home/aeb/tel +can be abbreviated +to +.I tel +when the current directory is +.IR /home/aeb . +.PP +The command +.I pwd +prints the current directory. +.PP +The command +.I cd +changes the current directory. +.PP +Try alternatively +.I cd +and +.I pwd +commands and explore +.I cd +usage: "cd", "cd .", "cd ..", "cd /", and "cd \[ti]". +.SS Directories +The command +.I mkdir +makes a new directory. +.PP +The command +.I rmdir +removes a directory if it is empty, and complains otherwise. +.PP +The command +.I find +(with a rather baroque syntax) will find files with given name +or other properties. +For example, "find . \-name tel" would find +the file +.I tel +starting in the present directory (which is called +.IR . ). +And "find / \-name tel" would do the same, but starting at the root +of the tree. +Large searches on a multi-GB disk will be time-consuming, +and it may be better to use +.BR locate (1). +.SS Disks and filesystems +The command +.I mount +will attach the filesystem found on some disk (or floppy, or CDROM or so) +to the big filesystem hierarchy. +And +.I umount +detaches it again. +The command +.I df +will tell you how much of your disk is still free. +.SS Processes +On a UNIX system many user and system processes run simultaneously. +The one you are talking to runs in the +.IR foreground , +the others in the +.IR background . +The command +.I ps +will show you which processes are active and what numbers these +processes have. +The command +.I kill +allows you to get rid of them. +Without option this is a friendly +request: please go away. +And "kill \-9" followed by the number +of the process is an immediate kill. +Foreground processes can often be killed by typing Control-C. +.SS Getting information +There are thousands of commands, each with many options. +Traditionally commands are documented on +.IR "man pages" , +(like this one), so that the command "man kill" will document +the use of the command "kill" (and "man man" document the command "man"). +The program +.I man +sends the text through some +.IR pager , +usually +.IR less . +Hit the space bar to get the next page, hit q to quit. +.PP +In documentation it is customary to refer to man pages +by giving the name and section number, as in +.BR man (1). +Man pages are terse, and allow you to find quickly some forgotten +detail. +For newcomers an introductory text with more examples +and explanations is useful. +.PP +A lot of GNU/FSF software is provided with info files. +Type "info info" +for an introduction on the use of the program +.IR info . +.PP +Special topics are often treated in HOWTOs. +Look in +.I /usr/share/doc/howto/en +and use a browser if you find HTML files there. +.\" +.\" Actual examples? Separate section for each of cat, cp, ...? +.\" gzip, bzip2, tar, rpm +.SH SEE ALSO +.BR ash (1), +.BR bash (1), +.BR chsh (1), +.BR csh (1), +.BR dash (1), +.BR ksh (1), +.BR locate (1), +.BR login (1), +.BR man (1), +.BR xterm (1), +.BR zsh (1), +.BR wait (2), +.BR stdout (3), +.BR man\-pages (7), +.BR standards (7) |