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| -rw-r--r-- | tcsh.html.markdown | 374 |
1 files changed, 187 insertions, 187 deletions
diff --git a/tcsh.html.markdown b/tcsh.html.markdown index 05954442..8f8429bc 100644 --- a/tcsh.html.markdown +++ b/tcsh.html.markdown @@ -28,23 +28,23 @@ Some more files: ```tcsh #!/bin/tcsh -# First line of the script is shebang which tells the system how to execute the -# script: http://en.wikipedia.org/wiki/Shebang_(Unix) -# TCSH emulates the shebang on systems which don't understand it. +# The first line of the script is a shebang which tells the system how to execute +# the script: http://en.wikipedia.org/wiki/Shebang_(Unix) +# TCSH emulates the shebang on systems that don't understand it. -# In most cases you'll use `#!/bin/tcsh -f', because `-f' option does not load +# In most cases you'll use `#!/bin/tcsh -f`, because `-f` option does not load # any resource or start-up files, or perform any command hashing, and thus # starts faster. # --- the echo command -------------------------------------------------------- -# The `echo' writes each word to the shell's standard output, separated by +# The `echo` writes each word to the shell's standard output, separated by # spaces and terminated with a newline. The echo_style shell variable may be # set to emulate (or not) the flags and escape sequences. # Display the value of echo_style echo $echo_style -# Enable `echo' to support backslashed characters and `-n' option (no new line) +# Enable `echo` to support backslashed characters and `-n` option (no new line) # This is the default for tcsh, but your distro may change it. Slackware has # done so. set echo_style = both @@ -65,17 +65,17 @@ echo 'two\nlines' # --- Basic Syntax ------------------------------------------------------------ # A special character (including a blank or tab) may be prevented from having -# its special meaning by preceding it with a backslash `\'. -# this will display the last history commands +# its special meaning by preceding it with a backslash `\`. +# This will display the last history commands echo !! -# this will not +# This will not echo \!\! -# Single quotes prevents expanding special characters too, but some -# characters like `!' and backslash have higher priority -# `$' (variable value) will not expands +# Single quotes prevent expanding special characters too, but some +# characters like `!` and backslash have higher priority +# `$` (variable value) will not expand echo '$1 tip' -# `!' (history) will expands +# `!` (history) will expand echo '!!' # Strings enclosed by back-quotes will be executed and replaced by the result. @@ -85,16 +85,16 @@ echo `ls` echo 'first line'; echo 'second line' # There is also conditional execution -echo "Always executed" || echo "Only executed if first command fails" -echo "Always executed" && echo "Only executed if first command does NOT fail" +echo "Always executed" || echo "Only executed if the first command fails" +echo "Always executed" && echo "Only executed if the first command does NOT fail" # Parenthesised commands are always executed in a subshell, -# example: create a project and then informs you that it finished while +# example: creates a project and then informs you that it finished while # it does the installation. make && ( espeak "BOSS, compilation finished"; make install ) -# prints the home directory but leaving you where you were +# prints the home directory but leaves you where you were (cd; pwd); pwd # Read tcsh man-page documentation @@ -103,10 +103,10 @@ man tcsh # --- Variables --------------------------------------------------------------- # The shell maintains a list of variables, each of which has as value a list of # zero or more words. The values of shell variables can be displayed and -# changed with the `set' and `unset' commands. -# The system maintains its own list of ``environment'' variables. -# These can be displayed and changed with `printenv', `setenv' and `unsetenv'. -# The syntax of setenv is similar to POSIX sh. +# changed with the `set` and `unset` commands. +# The system maintains its own list of "environment" variables. +# These can be displayed and changed with `printenv`, `setenv`, and `unsetenv`. +# The syntax of `setenv` is similar to POSIX sh. # Assign a value or nothing will create a variable # Assign nothing @@ -122,7 +122,7 @@ set var = `ls` # Remove a variable unset var -# Prints 1 (true) if the variable `var' exists otherwise prints 0 (false) +# Prints 1 (true) if the variable `var` exists otherwise prints 0 (false) echo $?var # Print all variables and their values set @@ -130,10 +130,10 @@ set # Prints the contents of 'var' echo $var; echo "$var"; -# Prints the string `$var' +# Prints the string `$var` echo \$var echo '$var' -# braces can be used to separate variable from the rest when its needed +# Braces can be used to separate variables from the rest when it is needed set num = 12; echo "There ${num}th element" # Prints the number of characters of the value: 6 @@ -147,7 +147,7 @@ echo $var echo $var[*] # Print the count of elements: 5 echo $#var -# Print indexed element; prints the second element: two +# Print the indexed element; This prints the second element: two echo $var[2] # Print range of elements; prints 2nd up to 3rd: two, three echo $var[2-3] @@ -165,8 +165,8 @@ echo $var[-3] # $! the PID of the last background process started by this shell # $$ script's PID -# $path, $PATH the list of directories that will search for executable to run -# $home, $HOME user's home directory, also the `~' can be used instead +# $path, $PATH the list of directories that will search for an executable to run +# $home, $HOME user's home directory, also the `~` can be used instead # $uid user's login ID # $user user's login name # $gid the user's group ID @@ -174,24 +174,24 @@ echo $var[-3] # $cwd, $PWD the Current/Print Working Directory # $owd the previous working directory # $tcsh tcsh version -# $tty the current tty; ttyN for linux console, pts/N for terminal +# $tty the current tty; ttyN for Linux console, pts/N for terminal # emulators under X # $term the terminal type # $verbose if set, causes the words of each command to be printed. -# can be set by the `-v' command line option too. +# can be set by the `-v` command line option too. # $loginsh if set, it is a login shell # TIP: $?0 is always false in interactive shells # TIP: $?prompt is always false in non-interactive shells -# TIP: if `$?tcsh' is unset; you run the original `csh' or something else; -# try `echo $shell' -# TIP: $verbose this is useful to debugging scripts -# NOTE: $PWD and $PATH are synchronised with $cwd and $pwd automatically. +# TIP: if `$?tcsh` is unset; you run the original `csh` or something else; +# try `echo $shell` +# TIP: `$verbose` is useful for debugging scripts +# NOTE: `$PWD` and `$PATH` are synchronised with `$cwd` and `$pwd` automatically. # --- Variable modifiers ------------------------------------------------------ # Syntax: ${var}:m[:mN] # Where <m> is: -# h : the directory t : the filenane r : remove extension e : the extension +# h : the directory t : the filename r : remove extension e : the extension # u : uppercase the first lowercase letter # l : lowercase the first uppercase letter # p : print but do not execute it (hist) @@ -199,8 +199,8 @@ echo $var[-3] # x : like q, but break into words at white spaces # g : apply the following modifier once to each word # a : apply the following modifier as many times as possible to single word -# s/l/r/ : search for `l' and replace with `r', not regex; the `&' in the r is -# replaced by l +# s/l/r/ : search for `l` and replace with `r`, not regex; the `&` in the `r` is +# replaced by `l` # & : Repeat the previous substitution # start with this file @@ -232,7 +232,7 @@ echo 'this string' >> file.txt echo 'this string' >>& file.txt # Redirect the standard input from file.txt cat < file.txt -# Input from keyboard; this stores the input line to variable `x' +# Input from keyboard; this stores the input line to variable `x` set x = $< # Document here; cat << LABEL @@ -243,7 +243,7 @@ LABEL (grep 'AGP' /usr/src/linux/Documentation/* > output-file.txt) >& error-file.txt # example: read a name from standard input and display a greetings message -echo -n "Enter your name? " +echo -n "Enter your name: " set name = $< echo "Greetings $name" @@ -266,15 +266,15 @@ if ( $name != $user ) echo "Your name isn't your username" # NOTE: if $name is empty, tcsh sees the above condition as: # if ( != $user ) ... # which is invalid syntax -# so the "safe" way to use potentially empty variables in tcsh is: +# The "safe" way to use potentially empty variables in tcsh is: # if ( "$name" != $user ) ... # which, when $name is empty, is seen by tcsh as: # if ( "" != $user ) ... # which works as expected # There is also conditional execution -echo "Always executed" || echo "Only executed if first command fails" -echo "Always executed" && echo "Only executed if first command does NOT fail" +echo "Always executed" || echo "Only executed if the first command fails" +echo "Always executed" && echo "Only executed if the first command does NOT fail" # To use && and || with if statements, you don't need multiple pairs of # square brackets: @@ -286,14 +286,14 @@ if ( "$name" == "Daniya" || "$name" == "Zach" ) then echo "This will run if $name is Daniya OR Zach." endif -# String matching operators ( `=~' and `!~' ) +# String matching operators ( `=~` and `!~` ) # The ‘==’ ‘!=’ ‘=~’ and ‘!~’ operators compare their arguments as strings; # all others operate on numbers. The operators ‘=~’ and ‘!~’ are like ‘!=’ # and ‘==’ except that the right hand side is a glob-pattern against which -# the left hand operand is matched. +# the left-hand operand is matched. if ( $user =~ ni[ck]* ) echo "Greetings Mr. Nicholas." -if ( $user !~ ni[ck]* ) echo "Hey, get out of Nicholas PC." +if ( $user !~ ni[ck]* ) echo "Hey, get out of Nicholas' PC." # Arithmetic expressions are denoted with the following format: @ result = 10 + 5 @@ -302,16 +302,16 @@ echo $result # Arithmetic Operators # +, -, *, /, % # -# Arithmetic Operators which must be parenthesised +# Arithmetic Operators which must be parenthesized # !, ~, |, &, ^, ~, <<, >>, # Compare and logical operators # -# All operators are same as in C. +# All operators are the same as in C. # It is non so well documented that numeric expressions require spaces -# in-between; Also, `@' has its own parser, it seems that work well when the -# expression is parenthesised otherwise the primary parser seems it is active. -# Parenthesis require spaces around, this is documented. +# in-between; Also, `@` has its own parser, it seems that it works well when +# the expression is parenthesized, otherwise the primary parser seems to be +# active. Parentheses require spaces around, this is documented. # wrong @ x = $y+1 @@ -330,32 +330,32 @@ echo $result # C's operators ++ and -- are supported if there is not assignment @ result ++ -# None shell created to do mathematics; +# No shell was created to do mathematics; # Except for the basic operations, use an external command with backslashes. # # I suggest the calc as the best option. # (http://www.isthe.com/chongo/tech/comp/calc/) # -# The standard Unix's bc as second option +# The standard Unix's bc as the second option # (https://www.gnu.org/software/bc/manual/html_mono/bc.html) # -# The standard Unix's AWK as third option +# The standard Unix's AWK as the third option # (https://www.gnu.org/software/gawk/manual/gawk.html) -# You can also use `perl', `php' or even several BASICs, but prefer the -# above utilities for faster load-and-run results. +# You can also use `Perl`, `PHP`, `python`, or even several BASICs, but prefer +# the above utilities for faster load-and-run results. # real example: (that I answer in StackExchange) # REQ: x := 1001b OR 0110b -# in `tcsh' expression (by using octal) +# in `tcsh` expression (by using octal) @ x = ( 011 | 06 ); echo $x -# the same by using `calc' (and using binary as the original req) +# the same by using `calc` (and using binary as the original req) set x = `calc '0b1001 | 0b110'`; echo $x # --- File Inquiry Operators -------------------------------------------------- -# NOTE: The builtin `filetest' command do the same thing. +# NOTE: The built-in `filetest` command does the same thing. #### Boolean operators # -r read access -w write access -x execute access -e existence @@ -366,23 +366,23 @@ set x = `calc '0b1001 | 0b110'`; echo $x # -b block device -c char device # -t file (digit) is an open file descriptor for a terminal device -# if the file `README' exists, displays a message +# If the file `README` exists, display a message if ( -e README ) echo "I have already README file" -# if the `less' program is installed, use this instead of `more' +# If the `less` program is installed, use it instead of `more` if ( -e `where less` ) then - alias more 'less' + alias more 'less' endif #### Non-boolean operators # -Z returns the file size in bytes # -M returns the modification time (mtime) -M: returns mtime string -# -A returns the lass access time (atime) -A: returns atime string -# -U returns the owners user ID -U: returns the owners user-name -# -G returns the group ID -G: returns the group-name +# -A returns the last access time (atime) -A: returns atime string +# -U returns the owner's user ID -U: returns the owner's user name +# -G returns the owner's group ID -G: returns the owner's group name # -P returns the permissions as octal number -Pmode returns perm. AND mode -# this will display the date as Unix-time integer: 1498511486 +# this will display the date as a Unix-time integer: 1498511486 filetest -M README.md # This will display "Tue Jun 27 00:11:26 2017" @@ -390,14 +390,14 @@ filetest -M: README.md # --- Basic Commands ---------------------------------------------------------- -# Navigate though file system with `chdir' (cd) +# Navigate through the filesystem with `chdir` (cd) cd path # change working directory -cd # change to home directory -cd - # change to previous directory +cd # change to the home directory +cd - # change to the previous directory cd .. # go up one directory # Examples: -cd ~/Downloads # go to my `Downloads' directory +cd ~/Downloads # go to my `Downloads` directory # Use `mkdir` to create new directories. mkdir newdir @@ -413,7 +413,7 @@ where csh # --- Pipe-lines -------------------------------------------------------------- # A pipeline is a sequence of processes chained together by their standard # streams, so that the output of each process (stdout) feeds directly as input -# (stdin) to the next one. This `pipes' are created with the `|' special +# (stdin) to the next one. These `pipes` are created with the `|` special # character and it is one of the most powerful characteristics of Unix. # example: @@ -422,18 +422,18 @@ ls -l | grep key | less # input (stdin) of the process for "grep key"; and likewise for the process # for "less". -# the `ls', the `grep' and the `less' are programs of Unix and they have their -# own man-page. The `pipe' mechanism is part of the kernel but the syntax -# and the control is job of the shell, the tcsh in our case. +# the `ls`, the `grep`, and the `less` are Unix programs and they have their +# own man-page. The `pipe` mechanism is part of the kernel but the syntax +# and the control is the shell's job, the tcsh in our case. -# 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. -# Microsoft still denied it but is well known bug since it is a common method -# for inter-process communication. For small I/O it will work well. -# tcsh, along with grep, gcc and perl is one of the first Unix programs that +# NOTE: Windows has the `pipe` mechanism too, but it is buggy and I signed it +# for all versions until Windows XP SP3 API32 which was the last one that I +# worked on. Microsoft denied it, but it is a well-known bug since it is a +# common method for inter-process communication. For small I/O it will work well. +# tcsh, along with grep, GCC, and Perl is one of the first Unix programs that # ported to DOS (with EMX DOS extender) and later to Windows (1998). -# example: this will convert tcsh to PostScript and will show it with okular +# example: this will convert tcsh to PostScript and will show it with Okular zcat /usr/man/man1/tcsh.1.gz | groff -Tps -man | okular - # a better version @@ -451,10 +451,10 @@ set page = tcsh; set loc = (locate -b -n 1 "\\\\"${page}".1.gz"); set page = tcsh; set loc = (locate -b -n 1 "\\\\"${page}".1.gz"); zcat `eval $loc` | groff -Tps -man | ps2pdf - ${page}.pdf && okular tcsh.pdf -# NOTE: `okular' is the default application of KDE environment and it shows -# postcript and pdf files. You can replace it with your lovely pdf viewer. -# zcat, locate, groff, are common programs in all Unices. `ps2pdf' program -# is part of `ghostscript' package that is widely used. +# NOTE: `okular` is the default application of the KDE environment and it shows +# postcript and pdf files. You can replace it with your lovely PDF viewer. +# `zcat`, `locate`, `groff`, are common programs in all Unixes. The `ps2pdf` +# program is part of the `ghostscript` package that is widely used. # --- Control Flow ------------------------------------------------------------ @@ -468,8 +468,8 @@ set page = tcsh; set loc = (locate -b -n 1 "\\\\"${page}".1.gz"); # ...] # 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 +# 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. # @@ -477,24 +477,24 @@ set page = tcsh; set loc = (locate -b -n 1 "\\\\"${page}".1.gz"); # # 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. +# If `expr` evaluates to true, then the command is executed. +# `command` must be a simple command, not an alias, a pipeline, a command list +#, or a parenthesized command list. With a few words, avoid using it. # -# BUG: Input/output redirection occurs even if expr is false and command is -# thus not executed. +# BUG: Input/output redirection occurs even if expr is false and the command +# is thus not executed. # -# check if we are in non-interactive shell and quit if true +# check if we are in a 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 + # 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 @@ -509,37 +509,37 @@ endif # # 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 +# 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 it's 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 + echo "$var is a man-page." + breaksw case *gz: - echo "$var is gzipped" - breaksw + echo "$var is gzipped" + breaksw default: - file $var + file $var endsw #### FOREACH-END # Syntax: # foreach name ( wordlist ) -# ... +# ... # [break | continue] # end # -# Successively sets the variable `name' to each member of `wordlist' and +# 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. +# `end` keyword. The `continue` keyword jumps 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. +# BUG: `foreach` doesn't ignore here documents when looking for its end. # example: counting 1 to 10 foreach i ( `seq 1 10` ) @@ -548,12 +548,12 @@ end # example: type all files in the list foreach f ( a.txt b.txt c.txt ) - cat $f + cat $f end # example: convert wma to ogg foreach f ( *.wma ) - ffmpeg -i "$f" "$f:r".ogg + ffmpeg -i "$f" "$f:r".ogg end #### WHILE-END @@ -562,22 +562,22 @@ end # [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 +# 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 ++ + echo $num + @ num ++ end # print all directories of CWD set lst = ( * ) while ( $#lst ) - if ( -d $lst[1] ) echo $lst[1] is directory - shift lst + if ( -d $lst[1] ) echo $lst[1] is directory + shift lst end # separate command-line arguments to options or parameters @@ -585,12 +585,12 @@ set options set params set lst = ( $* ) while ( $#lst ) - if ( "$lst[1]" =~ '-*' ) then - set options = ( $options $lst[1] ) - else - set params = ( $params $lst[1] ) - endif - shift lst + if ( "$lst[1]" =~ '-*' ) then + set options = ( $options $lst[1] ) + else + set params = ( $params $lst[1] ) + endif + shift lst end echo 'options =' $options echo 'parameters =' $params @@ -599,16 +599,16 @@ echo 'parameters =' $params # 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. +# 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' +# 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` 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. @@ -637,48 +637,48 @@ alias cd 'cd \!* && ls' #!/bin/tcsh -f set todo = option1 if ( $#argv > 0 ) then - set todo = $argv[1] + set todo = $argv[1] endif switch ( $todo ) case option1: -# ... - $0 results - breaksw +# ... + $0 results + breaksw case option2: -# ... - $0 results - breaksw +# ... + $0 results + breaksw case results: - echo "print the results here" -# ... - breaksw + echo "print the results here" +# ... + breaksw default: - echo "Unknown option: $todo" -# exit 0 + 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] +# otherwise it sets 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] + 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 + if ( $todo == $o ) then + # found; execute it + echo -n $todo > /sys/power/state + break + endif end # print help and exit echo "usage: $0 [option]" @@ -691,19 +691,19 @@ echo "available options on kernel: $opts" 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 + 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 --------------------------------------------------- @@ -711,36 +711,36 @@ 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 completion 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! +# * CSH is notorious for its bugs; +# * It is also famous for its advanced interactive mode. +# * TCSH is famous for having the most advanced completion subsystem. +# * TCSH is famous for having the most advanced aliases subsystem; aliases +# can take parameters and often be used as functions! +# * TCSH is well known and preferred by people (me too) because of better +# syntax. All shells are using Thomson's syntax with the exception of +# [t]csh, fish, and plan9's shells (rc, ex). +# * It is smaller and consumes far less memory than bash, zsh, and 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). +# * TCSH still has bugs; fewer, but it does; if you write readable clean code +# you'll find none; well almost none... This has to do with the implementation +# of csh; that doesn't mean the other shells have a good implementation. +# * no well-known shell is capable of regular programming; if your script +# is getting big, use a programming language, like Python, PHP, or Perl (good +# scripting 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 +# Advice: +# 1. Do not use redirection in single-line IFs (it is well documented bug) +# In most cases avoid using 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 +# A bug of csh was `set x=1` and `set x = 1` worked, but `set x =1` did not! +# 4. It is well documented that numeric expressions require spaces in between; +# also parenthesize 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. +# 7. Read the man page, `tcsh` has a huge number of options and variables. # # I suggest the following options enabled by default # -------------------------------------------------- @@ -770,14 +770,14 @@ end # 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: If the `backslash_quote` is set, it may create compatibility issues +# with other tcsh scripts that were written without it. # -# NOTE: The same for `parseoctal', but it is better to fix the problematic +# 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) +# This enables automatic rescanning of `path` directories if needed. (like bash) # set autorehash #### common aliases |