fix: tcsh.html.markdown

- replace tabs with 4 spaces
- fix markdown syntax 
- fix gramatical errors

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