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[tcsh/en] (#2777)
* Add files via upload tcsh/en added * Add files via upload [tcsh][en] * Add files via upload [tcsh][en] * Add files via upload [tcsh][en] * Add files via upload typos * Add files via upload typo at switch * Add files via upload tcsh/en added secret-num game as an example * Add files via upload competition -> completition * tcsh/en one more example to show when needed quotes at =~ and !~ * tcsh/en Clear explanation about what the '@' does
This commit is contained in:
Nicholas Christopoulos
ven
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tcsh.html.markdown
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tcsh.html.markdown
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---
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language: tcsh
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filename: LearnTCSH.csh
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contributors:
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- ["Nicholas Christopoulos", "https://github.com/nereusx"]
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lang: en
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---
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tcsh ("tee-see-shell") is a Unix shell based on and compatible with the C shell (csh).
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It is essentially the C shell with programmable command-line completion, command-line editing,
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and a few other features.
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It is the native root shell for BSD-based systems such as FreeBSD.
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Almost all Linux distros and BSD today use tcsh instead of the original csh. In
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most cases csh is a symbolic link that points to tcsh.
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This is because tcsh is backward compatible with csh, and the last
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is not maintained anymore.
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- [TCSH Home](http://www.tcsh.org/)
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- [TCSH Wikipedia](https://en.wikipedia.org/wiki/Tcsh)
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- [TCSH manual page](http://www.tcsh.org/tcsh.html/top.html)
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- [“An Introduction to the C shell”, William Joy](https://docs.freebsd.org/44doc/usd/04.csh/paper.html)
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- [TCSH Bug reports and/or features requests](https://bugs.gw.com/)
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Some more files:
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[tcsh help command (for 132x35 terminal size)](https://github.com/nereusx/dotfiles/blob/master/csh-help),
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[my ~/.tcshrc](https://github.com/nereusx/dotfiles/blob/master/.tcshrc)
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```tcsh
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#!/bin/tcsh
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# First line of the script is shebang which tells the system how to execute the
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# script: http://en.wikipedia.org/wiki/Shebang_(Unix)
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# TCSH emulates the shebang on systems which don't understand it.
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# In most cases you'll use `#!/bin/tcsh -f', because `-f' option does not load
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# any resource or start-up files, or perform any command hashing, and thus
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# starts faster.
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# --- the echo command --------------------------------------------------------
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# The `echo' writes each word to the shell's standard output, separated by
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# spaces and terminated with a newline. The echo_style shell variable may be
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# set to emulate (or not) the flags and escape sequences.
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# Display the value of echo_style
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echo $echo_style
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# Enable `echo' to support backslashed characters and `-n' option (no new line)
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# This is the default for tcsh, but your distro may change it. Slackware has
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# done so.
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set echo_style = both
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# Prints "Hello world"
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echo Hello world
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echo "Hello world"
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echo 'Hello world'
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echo `echo Hello world`
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# This prints "twonlines" in one line
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echo two\nlines
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# Prints the two lines
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echo "two\nlines"
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echo 'two\nlines'
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# --- Basic Syntax ------------------------------------------------------------
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# A special character (including a blank or tab) may be prevented from having
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# its special meaning by preceding it with a backslash `\'.
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# this will display the last history commands
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echo !!
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# this will not
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echo \!\!
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# Single quotes prevents expanding special characters too, but some
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# characters like `!' and backslash have higher priority
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# `$' (variable value) will not expands
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echo '$1 tip'
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# `!' (history) will expands
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echo '!!'
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# Strings enclosed by back-quotes will be executed and replaced by the result.
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echo `ls`
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# Semi-colon separate commands
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echo 'first line'; echo 'second line'
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# There is also conditional execution
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echo "Always executed" || echo "Only executed if first command fails"
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echo "Always executed" && echo "Only executed if first command does NOT fail"
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# Parenthesised commands are always executed in a subshell,
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# example: create a project and then informs you that it finished while
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# it does the installation.
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make && ( espeak "BOSS, compilation finished"; make install )
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# prints the home directory but leaving you where you were
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(cd; pwd); pwd
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# Read tcsh man-page documentation
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man tcsh
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# --- Variables ---------------------------------------------------------------
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# The shell maintains a list of variables, each of which has as value a list of
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# zero or more words. The values of shell variables can be displayed and
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# changed with the `set' and `unset' commands.
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# The system maintains its own list of ``environment'' variables.
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# These can be displayed and changed with `printenv', `setenv' and `unsetenv'.
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# The syntax of setenv is similar to POSIX sh.
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# Assign a value or nothing will create a variable
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# Assign nothing
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set var
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# Assign a numeric value
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# the '@' denotes the expression is arithmetic; it works similar to 'set' but
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# the right value can be a numeric expression.
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@ var = 1 + 2
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# Assign a string value
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set var = "Hello, I am the contents of 'var' variable"
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# Assign the output of a program
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set var = `ls`
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# Remove a variable
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unset var
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# Prints 1 (true) if the variable `var' exists otherwise prints 0 (false)
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echo $?var
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# Print all variables and their values
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set
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# Prints the contents of 'var'
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echo $var;
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echo "$var";
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# Prints the string `$var'
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echo \$var
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echo '$var'
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# braces can be used to separate variable from the rest when its needed
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set num = 12; echo "There ${num}th element"
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# Prints the number of characters of the value: 6
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set var = '123456'; echo $%var
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### LISTs
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# Assign a list of values
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set var = ( one two three four five )
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# Print all the elements: one two three four five
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echo $var
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echo $var[*]
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# Print the count of elements: 5
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echo $#var
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# Print indexed element; prints the second element: two
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echo $var[2]
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# Print range of elements; prints 2nd up to 3rd: two, three
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echo $var[2-3]
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# Prints all elements starting from the 3rd: three four five
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echo $var[3-]
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# Prints print all up to 3rd element: one two three
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echo $var[-3]
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### Special Variables
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# $argv list of command-line arguments
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# $argv[0] this file-name (the file of the script file)
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# $# $0, $n, $* are the same as $#argv, $argv[0], $argv[n], $argv[*]
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# $status, $? the exit code of the last command that executed
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# $_ the previous command line
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# $! the PID of the last background process started by this shell
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# $$ script's PID
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# $path, $PATH the list of directories that will search for executable to run
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# $home, $HOME user's home directory, also the `~' can be used instead
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# $uid user's login ID
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# $user user's login name
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# $gid the user's group ID
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# $group the user's group-name
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# $cwd, $PWD the Current/Print Working Directory
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# $owd the previous working directory
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# $tcsh tcsh version
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# $tty the current tty; ttyN for linux console, pts/N for terminal
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# emulators under X
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# $term the terminal type
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# $verbose if set, causes the words of each command to be printed.
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# can be set by the `-v' command line option too.
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# $loginsh if set, it is a login shell
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# TIP: $?0 is always false in interactive shells
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# TIP: $?prompt is always false in non-interactive shells
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# TIP: if `$?tcsh' is unset; you run the original `csh' or something else;
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# try `echo $shell'
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# TIP: $verbose this is useful to debugging scripts
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# NOTE: $PWD and $PATH are synchronised with $cwd and $pwd automatically.
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# --- Variable modifiers ------------------------------------------------------
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# Syntax: ${var}:m[:mN]
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# Where <m> is:
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# h : the directory t : the filenane r : remove extension e : the extension
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# u : uppercase the first lowercase letter
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# l : lowercase the first uppercase letter
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# p : print but do not execute it (hist)
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# q : quote the substituted words, preventing further substitutions
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# x : like q, but break into words at white spaces
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# g : apply the following modifier once to each word
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# a : apply the following modifier as many times as possible to single word
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# s/l/r/ : search for `l' and replace with `r', not regex; the `&' in the r is
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# replaced by l
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# & : Repeat the previous substitution
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# start with this file
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set f = ~/Documents/Alpha/beta.txt
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# prints ~/Documents/Alpha/beta
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echo $f:r
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# prints ~/Documents/Alpha
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echo $f:h
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# prints beta.txt
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echo $f:t
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# prints txt
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echo $f:e
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# prints beta
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echo $f:t:r
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# prints Beta
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echo $f:t:r:u
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# prints Biota
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echo $f:t:r:u:s/eta/iota/
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# --- Redirection -------------------------------------------------------------
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# Create file.txt and write the standard output to it
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echo 'this string' > file.txt
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# Create file.txt and write the standard output and standard error to it
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echo 'this string' >& file.txt
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# Append the standard output to file.txt
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echo 'this string' >> file.txt
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# Append the standard output and standard error to file.txt
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echo 'this string' >>& file.txt
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# Redirect the standard input from file.txt
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cat < file.txt
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# Input from keyboard; this stores the input line to variable `x'
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set x = $<
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# Document here;
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cat << LABEL
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...text here...
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LABEL
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# TIP: this is how to get standard error separated:
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(grep 'AGP' /usr/src/linux/Documentation/* > output-file.txt) >& error-file.txt
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# example: read a name from standard input and display a greetings message
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echo -n "Enter your name? "
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set name = $<
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echo "Greetings $name"
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# --- Expressions ------------------------------------------------------------
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# Operators:
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# == equal != not equal ! not
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# > greater than < less than >= greater or equal <= less or equal
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# && logical AND || logical OR
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if ( $name != $user ) then
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echo "Your name isn't your username"
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else
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echo "Your name is your username"
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endif
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# single-line form
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if ( $name != $user ) echo "Your name isn't your username"
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# NOTE: if $name is empty, tcsh sees the above condition as:
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# if ( != $user ) ...
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# which is invalid syntax
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# so the "safe" way to use potentially empty variables in tcsh is:
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# if ( "$name" != $user ) ...
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# which, when $name is empty, is seen by tcsh as:
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# if ( "" != $user ) ...
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# which works as expected
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# There is also conditional execution
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echo "Always executed" || echo "Only executed if first command fails"
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echo "Always executed" && echo "Only executed if first command does NOT fail"
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# To use && and || with if statements, you don't need multiple pairs of
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# square brackets:
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if ( "$name" == "Steve" && "$age" == 15 ) then
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echo "This will run if $name is Steve AND $age is 15."
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endif
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if ( "$name" == "Daniya" || "$name" == "Zach" ) then
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echo "This will run if $name is Daniya OR Zach."
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endif
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# String matching operators ( `=~' and `!~' )
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# The ‘==’ ‘!=’ ‘=~’ and ‘!~’ operators compare their arguments as strings;
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# all others operate on numbers. The operators ‘=~’ and ‘!~’ are like ‘!=’
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# and ‘==’ except that the right hand side is a glob-pattern against which
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# the left hand operand is matched.
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if ( $user =~ ni[ck]* ) echo "Greetings Mr. Nicholas."
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if ( $user !~ ni[ck]* ) echo "Hey, get out of Nicholas PC."
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# Arithmetic expressions are denoted with the following format:
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@ result = 10 + 5
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echo $result
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# Arithmetic Operators
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# +, -, *, /, %
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#
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# Arithmetic Operators which must be parenthesised
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# !, ~, |, &, ^, ~, <<, >>,
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# Compare and logical operators
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#
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# All operators are same as in C.
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# It is non so well documented that numeric expressions require spaces
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# in-between; Also, `@' has its own parser, it seems that work well when the
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# expression is parenthesised otherwise the primary parser seems it is active.
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# Parenthesis require spaces around, this is documented.
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# wrong
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@ x = $y+1
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@ x = 0644 & 022; echo $x
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@ x = (0644 & 022) +1; echo $x
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@ x = (0644 & 022)+ 1; echo $x
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@ x = ( ~077 ); echo $x
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# correct
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@ x = $y + 1
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@ x = ( 0644 & 022 ) + 1; echo $x
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@ x = ( ~ 077 ); echo $x
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@ x = ( ~ 077 | 022 ); echo $x
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@ x = ( ! 0 ); echo $x
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# C's operators ++ and -- are supported if there is not assignment
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@ result ++
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# None shell created to do mathematics;
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# Except for the basic operations, use an external command with backslashes.
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#
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# I suggest the calc as the best option.
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# (http://www.isthe.com/chongo/tech/comp/calc/)
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#
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# The standard Unix's bc as second option
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# (https://www.gnu.org/software/bc/manual/html_mono/bc.html)
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#
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# The standard Unix's AWK as third option
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# (https://www.gnu.org/software/gawk/manual/gawk.html)
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# You can also use `perl', `php' or even several BASICs, but prefer the
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# above utilities for faster load-and-run results.
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# real example: (that I answer in StackExchange)
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# REQ: x := 1001b OR 0110b
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# in `tcsh' expression (by using octal)
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@ x = ( 011 | 06 ); echo $x
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# the same by using `calc' (and using binary as the original req)
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set x = `calc '0b1001 | 0b110'`; echo $x
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# --- File Inquiry Operators --------------------------------------------------
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# NOTE: The builtin `filetest' command do the same thing.
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#### Boolean operators
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# -r read access -w write access -x execute access -e existence
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# -f plain file -d directory -l symbolic link -p named pipe
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# -S socket file
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# -o ownership -z zero size -s non-zero size
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# -u SUID is set -g SGID is set -k sticky is set
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# -b block device -c char device
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# -t file (digit) is an open file descriptor for a terminal device
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# if the file `README' exists, displays a message
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if ( -e README ) echo "I have already README file"
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# if the `less' program is installed, use this instead of `more'
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if ( -e `where less` ) then
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alias more 'less'
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endif
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#### Non-boolean operators
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# -Z returns the file size in bytes
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# -M returns the modification time (mtime) -M: returns mtime string
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# -A returns the lass access time (atime) -A: returns atime string
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# -U returns the owners user ID -U: returns the owners user-name
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# -G returns the group ID -G: returns the group-name
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# -P returns the permissions as octal number -Pmode returns perm. AND mode
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# this will display the date as Unix-time integer: 1498511486
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filetest -M README.md
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# This will display "Tue Jun 27 00:11:26 2017"
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filetest -M: README.md
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# --- Basic Commands ----------------------------------------------------------
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# Navigate though file system with `chdir' (cd)
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cd path # change working directory
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cd # change to home directory
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cd - # change to previous directory
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||||
cd .. # go up one directory
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||||
# Examples:
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||||
cd ~/Downloads # go to my `Downloads' directory
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||||
# Use `mkdir` to create new directories.
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mkdir newdir
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||||
# The `-p` flag causes new intermediate directories to be created as necessary.
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mkdir -p ~/.backup/saves
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# which & where
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||||
# find if csh points to tcsh
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ls -lha `which csh`
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||||
# find if csh is installed on more than one directory
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||||
where csh
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||||
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||||
# --- Pipe-lines --------------------------------------------------------------
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||||
# A pipeline is a sequence of processes chained together by their standard
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||||
# streams, so that the output of each process (stdout) feeds directly as input
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||||
# (stdin) to the next one. This `pipes' are created with the `|' special
|
||||
# character and it is one of the most powerful characteristics of Unix.
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||||
# example:
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||||
ls -l | grep key | less
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# "ls -l" produces a process, the output (stdout) of which is piped to the
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# input (stdin) of the process for "grep key"; and likewise for the process
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||||
# for "less".
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||||
# the `ls', the `grep' and the `less' are programs of Unix and they have their
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# own man-page. The `pipe' mechanism is part of the kernel but the syntax
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||||
# and the control is job of the shell, the tcsh in our case.
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||||
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||||
# NOTE: `pipe' mechanism has Windows too, but it is buggy and I sign it for all
|
||||
# versions until Windows XP SP3 API32 which was the last one that I worked on.
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||||
# Microsoft still denied it but is well known bug since it is a common method
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||||
# for inter-process communication. For small I/O it will work well.
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||||
# tcsh, along with grep, gcc and perl is one of the first Unix programs that
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||||
# ported to DOS (with EMX DOS extender) and later to Windows (1998).
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||||
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||||
# example: this will convert tcsh to PostScript and will show it with okular
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||||
zcat /usr/man/man1/tcsh.1.gz | groff -Tps -man | okular -
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||||
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||||
# a better version
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||||
zcat `locate -b -n 1 '\tcsh.1.gz'` | groff -Tps -man | okular -
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||||
# even better
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||||
set page = tcsh; set loc = (locate -b -n 1 "\\\\"${page}".1.gz");
|
||||
zcat `eval $loc` | groff -Tps -man | okular -
|
||||
|
||||
# the same, modified to create man page pdf
|
||||
set page = tcsh; set loc = (locate -b -n 1 "\\\\"${page}".1.gz");
|
||||
zcat `eval $loc` | groff -Tps -man | ps2pdf - ${page}.pdf
|
||||
|
||||
# the same, but now shows the ${page}.pdf too
|
||||
set page = tcsh; set loc = (locate -b -n 1 "\\\\"${page}".1.gz");
|
||||
zcat `eval $loc` | groff -Tps -man | ps2pdf - ${page}.pdf && okular tcsh.pdf
|
||||
|
||||
# NOTE: `okular' is the default application of KDE environment and it shows
|
||||
# postcript and pdf files. You can replace it with your lovely pdf viewer.
|
||||
# zcat, locate, groff, are common programs in all Unices. `ps2pdf' program
|
||||
# is part of `ghostscript' package that is widely used.
|
||||
|
||||
# --- Control Flow ------------------------------------------------------------
|
||||
|
||||
#### IF-THEN-ELSE-ENDIF
|
||||
# Syntax:
|
||||
# if ( expr ) then
|
||||
# ...
|
||||
# [else if ( expr2 ) then
|
||||
# ...]
|
||||
# [else
|
||||
# ...]
|
||||
# endif
|
||||
#
|
||||
# If the specified expr is true then the commands to the first else are
|
||||
# executed; otherwise if expr2 is true then the commands to the second else
|
||||
# are executed, etc.
|
||||
# Any number of else-if pairs are possible; only one endif is needed.
|
||||
#
|
||||
# Single-line form:
|
||||
#
|
||||
# if ( expr ) command
|
||||
#
|
||||
# If `expr' evaluates true, then command is executed.
|
||||
# `command' must be a simple command, not an alias, a pipeline, a command list
|
||||
# or a parenthesized command list. With few words, avoid to use it.
|
||||
#
|
||||
# BUG: Input/output redirection occurs even if expr is false and command is
|
||||
# thus not executed.
|
||||
#
|
||||
|
||||
# check if we are in non-interactive shell and quit if true
|
||||
if ( $?USER == 0 || $?prompt == 0 ) exit
|
||||
|
||||
# check if we are a login shell
|
||||
if ( $?loginsh ) then
|
||||
# check if you are on linux console (not X's terminal)
|
||||
if ( $tty =~ tty* ) then
|
||||
# enable keypad application keys (man console_codes)
|
||||
echo '\033='
|
||||
endif
|
||||
endif
|
||||
|
||||
#### SWITCH-ENDSW
|
||||
# Syntax:
|
||||
# switch ( expr )
|
||||
# case pattern:
|
||||
# ...
|
||||
# [breaksw]
|
||||
# [default:
|
||||
# ...]
|
||||
# endsw
|
||||
#
|
||||
# tcsh uses a case statement that works similarly to switch in C.
|
||||
# Each case label is successively matched, against the specified string which
|
||||
# is first command and filename expanded. The file metacharacters `*', `?'
|
||||
# and `[...]' may be used in the case labels. If none of the labels match the
|
||||
# execution begins after the default label if its defined.
|
||||
# The command `breaksw' causes execution to continue after the endsw. Otherwise
|
||||
# control may fall through case labels and default labels as in C.
|
||||
|
||||
switch ( $var )
|
||||
case *.[1-9]:
|
||||
case *.[1-9].gz:
|
||||
echo "$var is a man-page."
|
||||
breaksw
|
||||
case *gz:
|
||||
echo "$var is gzipped"
|
||||
breaksw
|
||||
default:
|
||||
file $var
|
||||
endsw
|
||||
|
||||
#### FOREACH-END
|
||||
# Syntax:
|
||||
# foreach name ( wordlist )
|
||||
# ...
|
||||
# [break | continue]
|
||||
# end
|
||||
#
|
||||
# Successively sets the variable `name' to each member of `wordlist' and
|
||||
# executes the sequence of commands between this command and the matching
|
||||
# `end' keyword. The `continue' keyword jump to the next element back to
|
||||
# top; and the `break' keyword terminates the loop.
|
||||
#
|
||||
# BUG: `foreach' doesn't ignore here documents when looking for its end.
|
||||
|
||||
# example: counting 1 to 10
|
||||
foreach i ( `seq 1 10` )
|
||||
echo $i
|
||||
end
|
||||
|
||||
# example: type all files in the list
|
||||
foreach f ( a.txt b.txt c.txt )
|
||||
cat $f
|
||||
end
|
||||
|
||||
# example: convert wma to ogg
|
||||
foreach f ( *.wma )
|
||||
ffmpeg -i "$f" "$f:r".ogg
|
||||
end
|
||||
|
||||
#### WHILE-END
|
||||
# while ( expr )
|
||||
# ...
|
||||
# [break | continue]
|
||||
# end
|
||||
#
|
||||
# Executes the commands between the `while' and the matching `end' while `expr'
|
||||
# evaluates non-zero. `break' and `continue' may be used to terminate or
|
||||
# continue the loop prematurely.
|
||||
|
||||
# count from 1 to 10
|
||||
set num = 1
|
||||
while ( $num <= 10 )
|
||||
echo $num
|
||||
@ num ++
|
||||
end
|
||||
|
||||
# print all directories of CWD
|
||||
set lst = ( * )
|
||||
while ( $#lst )
|
||||
if ( -d $lst[1] ) echo $lst[1] is directory
|
||||
shift lst
|
||||
end
|
||||
|
||||
# separate command-line arguments to options or parameters
|
||||
set options
|
||||
set params
|
||||
set lst = ( $* )
|
||||
while ( $#lst )
|
||||
if ( "$lst[1]" =~ '-*' ) then
|
||||
set options = ( $options $lst[1] )
|
||||
else
|
||||
set params = ( $params $lst[1] )
|
||||
endif
|
||||
shift lst
|
||||
end
|
||||
echo 'options =' $options
|
||||
echo 'paramaters =' $params
|
||||
|
||||
#### REPEAT
|
||||
# Syntax: repeat count command
|
||||
#
|
||||
# The specified command, which is subject to the same restrictions as the
|
||||
# command in the one line if statement above, is executed count times.
|
||||
# I/O redirections occur exactly once, even if count is 0.
|
||||
#
|
||||
# TIP: in most cases prefer `while'
|
||||
|
||||
repeat 3 echo "ding dong"
|
||||
|
||||
# --- Functions ---------------------------------------------------------------
|
||||
# tcsh has no functions but its expression syntax is advanced enough to use
|
||||
# `alias' as functions. Another method is recursion
|
||||
|
||||
# Alias argument selectors; the ability to define an alias to take arguments
|
||||
# supplied to it and apply them to the commands that it refers to.
|
||||
# Tcsh is the only shell that provides this feature.
|
||||
#
|
||||
# \!# argument selector for all arguments, including the alias/command
|
||||
# itself; arguments need not be supplied.
|
||||
# \!* argument selector for all arguments, excluding the alias/command;
|
||||
# arguments need not be supplied.
|
||||
# \!$ argument selector for the last argument; argument need not be supplied,
|
||||
# but if none is supplied, the alias name is considered to be the
|
||||
# last argument.
|
||||
# \!^ argument selector for first argument; argument MUST be supplied.
|
||||
# \!:n argument selector for the nth argument; argument MUST be supplied;
|
||||
# n=0 refers to the alias/command name.
|
||||
# \!:m-n argument selector for the arguments from the mth to the nth;
|
||||
# arguments MUST be supplied.
|
||||
# \!:n-$ argument selector for the arguments from the nth to the last;
|
||||
# at least argument n MUST be supplied.
|
||||
|
||||
# Alias the cd command so that when you change directories, the contents
|
||||
# are immediately displayed.
|
||||
alias cd 'cd \!* && ls'
|
||||
|
||||
# --- Recursion method --- begin ---
|
||||
#!/bin/tcsh -f
|
||||
set todo = option1
|
||||
if ( $#argv > 0 ) then
|
||||
set todo = $argv[1]
|
||||
endif
|
||||
|
||||
switch ( $todo )
|
||||
case option1:
|
||||
# ...
|
||||
$0 results
|
||||
breaksw
|
||||
case option2:
|
||||
# ...
|
||||
$0 results
|
||||
breaksw
|
||||
case results:
|
||||
echo "print the results here"
|
||||
# ...
|
||||
breaksw
|
||||
default:
|
||||
echo "Unknown option: $todo"
|
||||
# exit 0
|
||||
endsw
|
||||
# --- Recursion method --- end ---
|
||||
|
||||
# --- examples ----------------------------------------------------------------
|
||||
|
||||
# this script prints available power-states if no argument is set;
|
||||
# otherwise it set the state of the $argv[1]
|
||||
# --- power-state script --- begin --------------------------------------------
|
||||
#!/bin/tcsh -f
|
||||
# get parameter ("help" for none)
|
||||
set todo = help
|
||||
if ( $#argv > 0 ) then
|
||||
set todo = $argv[1]
|
||||
endif
|
||||
# available options
|
||||
set opts = `cat /sys/power/state`
|
||||
# is known?
|
||||
foreach o ( $opts )
|
||||
if ( $todo == $o ) then
|
||||
# found; execute it
|
||||
echo -n $todo > /sys/power/state
|
||||
break
|
||||
endif
|
||||
end
|
||||
# print help and exit
|
||||
echo "usage: $0 [option]"
|
||||
echo "available options on kernel: $opts"
|
||||
# --- power-state script --- end ----------------------------------------------
|
||||
|
||||
# Guess the secret number game
|
||||
# --- secretnum.csh --- begin -------------------------------------------------
|
||||
#!/bin/tcsh -f
|
||||
set secret=`shuf -i1-100 -n1`
|
||||
echo "I have a secret number from 1 up to 100"
|
||||
while ( 1 )
|
||||
echo -n "Guess: "
|
||||
set guess = $<
|
||||
if ( $secret == $guess ) then
|
||||
echo "You found it"
|
||||
exit 1
|
||||
else
|
||||
if ( $secret > $guess ) then
|
||||
echo "its greater"
|
||||
else if ( $secret < $guess ) then
|
||||
echo "its lesser"
|
||||
endif
|
||||
endif
|
||||
endif
|
||||
end
|
||||
# --- secretnum.csh --- end ---------------------------------------------------
|
||||
|
||||
# -----------------------------------------------------------------------------
|
||||
# Appendices
|
||||
|
||||
#### About [T]CSH:
|
||||
# * CSH is notorious about its bugs;
|
||||
# * It was also famous about its advanced interactive mode.
|
||||
# * TCSH is famous that have the most advanced completition subsystem.
|
||||
# * TCSH is famous that have the most advanced aliases subsystem; aliases
|
||||
# can take parameters and often used as functions!
|
||||
# * TCSH is well known that preferred by people (me too) because of better
|
||||
# syntax. All shells are using Thomson's syntax with exception of [t]csh,
|
||||
# fish and plan9's shells (rc, ex).
|
||||
# * It is smaller and consume far less memory than bash, zsh even mksh!
|
||||
# (memusage reports)
|
||||
# * TCSH still has bugs; less but have; if you write readable clean code you'll
|
||||
# find none; well almost none... This has to do with the implementation of
|
||||
# csh; that no means the other shells has good implementation.
|
||||
# * no one well known shell is capable for regular programming; if your script
|
||||
# getting big, use a programming language, or at least PHP or Perl (good
|
||||
# script languages).
|
||||
#
|
||||
# Advises:
|
||||
# 1. Do not use redirection in single-line if (it is well documented bug)
|
||||
# In most cases avoid to use single-line IFs.
|
||||
# 2. Do not mess up with other shells code, c-shell is not compatible with
|
||||
# other shells and has different abilities and priorities.
|
||||
# 3. Use spaces as you'll use them to write readable code in any language.
|
||||
# A bug of csh was `set x=1' worked, `set x = 1' worked, `set x =1' did not!
|
||||
# 4. It is well documented that numeric expressions require spaces in-between;
|
||||
# also parenthesise all bit-wise and unary operators.
|
||||
# 5. Do not write a huge weird expression with several quotes, backslashes etc
|
||||
# It is bad practice for generic programming, it is dangerous in any shell.
|
||||
# 6. Help tcsh, report the bug here <https://bugs.gw.com/>
|
||||
# 7. Read the man page, `tcsh' has huge number of options, and variables.
|
||||
#
|
||||
# I suggest the following options enabled by default
|
||||
# --------------------------------------------------
|
||||
# Even in non-interactive shells
|
||||
# set echo_style=both
|
||||
# set backslash_quote
|
||||
# set parseoctal
|
||||
# unset noclobber
|
||||
#
|
||||
# Whatever...
|
||||
# set inputmode=insert
|
||||
# set autolist
|
||||
# set listjobs
|
||||
# set padhour
|
||||
# set color
|
||||
# set colorcat
|
||||
# set nobeep
|
||||
# set cdtohome
|
||||
#
|
||||
# set histdup
|
||||
# set histlit
|
||||
# set nohistclop
|
||||
#
|
||||
# unset compat_expr
|
||||
# unset noglob
|
||||
# unset autologout
|
||||
# unset time
|
||||
# unset tperiod
|
||||
#
|
||||
# NOTE: If the `backslash_quote' is set, it may create compatibility issues
|
||||
# with other tcsh scripts which was written without it.
|
||||
#
|
||||
# NOTE: The same for `parseoctal', but it is better to fix the problematic
|
||||
# scripts.
|
||||
#
|
||||
# NOTE: **for beginners only**
|
||||
# This enable automatically rescan `path' directories if need to. (like bash)
|
||||
# set autorehash
|
||||
|
||||
#### common aliases
|
||||
# alias hist 'history 20'
|
||||
# alias ll 'ls --color -lha'
|
||||
# alias today "date '+%d%h%y'
|
||||
# alias ff 'find . -name '
|
||||
|
||||
#### a nice prompt
|
||||
# set prompt = "%B%{\033[35m%}%t %{\033[32m%}%n@%m%b %C4 %# "
|
||||
```
|
||||
Loading…
Reference in New Issue
Block a user