[Code] Équivalence Bash vs Powershell

Excellent tableau comparatif entre Bash (scripting shell) et PowerShell (scripting PowerShell
windows) qui peut être intéressant de voir si on connait l'un des deux langages et que l'on souhaite se mettre à l'autre !



Source : http://cecs.wright.edu/~pmateti/Courses/233/Labs/Scripting/bashVsPowerShellTable.html

bash	PowerShell	Description
Scripting Basics
Put a "shebang" at the beginning of the file:  #!/bin/bash Change permissions on script file to allow execution.	Give the file a ps1 extension. For downloaded scripts, unblock the file under file properties in Windows Explorer.	Steps for making scripting files run. In PowerShell, the first time you do scripting, you will need to set the appropriate security settings: run PowerShell as administrator and type set-executionpolicy remotesigned.
source (or) .	.	shell built-in: execute the commands in a file
echo String	echo String (or) Write-Host String	Prints String to the screen. In PowerShell, Write-Hostforces the output to the screen instead of being a return value.
var=0 (No spaces around =)	$var = 0	Creates a variable $var. In BASH, do not put whitespace around the equals sign, and do not use a $ in the variable assignment.
let var=$var+5 (or) var=$(( $var + 5 ))	$var += 5	Add 5 to $var
# comment	# comment	A comment
Strings
= !=	-eq -ne -ceq -cne	String comparisons. In BASH, be sure the strings litereals are in quotes.
"" | gm		Get a list of non-static string members
[string] | gm -static		Get a list of static string members
${string#text_to_remove}	string.TrimStart("characters")	Removes the specified characters/text from the beginning of the string.
${string%text_to_remove}	string.TrimEnd("characters")	Removes the specified characters/text from the end of the string.  Suppose $fnm == helloThere.txt; then ${fnm%.???} is helloThere
Pattern Matching
grep	select-string	print lines matching a pattern
sed	-replace	performs string transformations
Booleans and Conditions
true  false	$true  $false	Boolean literals
-lt -gt -le -ge -eq -ne	-lt -gt -le -ge -eq -ne	Arithmetic relational operators
	-like	True if a string matches a wildcard pattern
	-match	True if a string matches a regular expressions
	Where-Object { condition }	Used to filter input by a condition. Remember that $_ refers to the current object being tested.
-z $var	$var -eq $null	True if $var is null
-n $var	$var -ne $null	True if $var is not null (contains one or more characters)
-o -a	-or -and	Logical or and and
-e file	Test-Path file	True if file exists.
! -e file	! (Test-Path file)	True if file does not exist.
-d file	file.PSISContainer	True if file is a directory. In PowerShell, if file is not a file variable, be sure to get the file object first with gi.
-s file		True if file exists and has a size greater than zero.
file1 -nt file2		True if file1 is newer (according to modification date) than file2
file1 -ot file2		True if file1 is older (according to modification date) than file2
Control Structures
if [ condition ] then    codeblock fi	if (condition) {    codeblock }	If statement. In BASH, be sure to leave a space between the condition and the bracket.
if [ condition ] then    codeblock elif [ condition ] then    codeblock else    codeblock fi	if (condition) {    codeblock } elseif (condition) {    codeblock } else {    codeblock }	If - else if - else statement
var=0 while [ $var -lt 10 ] do    echo $var    var=$(( $var + 1 )) done	$var = 0 while ($var -lt 10) {    echo $var    $var++ }	Prints numbers 0 through 9.
for ((i=0; i < 10; i++)) do    echo $i done	for ($i=0;$i -lt 10; $i++) {    echo $i }	Prints numbers 0 through 9.
for var in $array do    codeblock done	foreach ($var in $array) {    codeblock }	For each loop
continue  break	continue  break	Loop controls: continue stops current loop iteration and begins the next; break exits the loop currently being executed.
basename file	file.name	The name of file without the path. In PowerShell, remember to first get the file object.
dirname file	file.directoryname	The name directory file is in. In PowerShell, remember to first get the file object.
stat -c%s $file (or) $(stat -c%s $file)	file.length	The number of bytes in file. In PowerShell, remember to first get the file object.
	file.LastWriteTime	The last modified time for file. Remember to first get the file object.
files=`ls` (or) files=$(ls) (or) files=*	$files = Get-Item *	Store a list of the files in the current working directory in $files. In PowerShell, check out the -exclude flag as well as the Get-ChildItem cmdlet.
|  >  >>  2>  2>>	|  >  >>  2>  2>>	Piping, output and error redirection. In BASH, output redirected to /dev/null is gone. In PowerShell, output redirected to $null is gone.
printArg() {    echo $1 }	function printArg {    param ($p1)    echo $p1 }	function to print the first argument to the screen.
return_five() {    return 5 } return_five echo $?	function return_five {    echo 5  (or)  return 5 } $value = return_five echo $value	Function returns 5, which is printed after the function call. In PowerShell, any output in a function that is not caught is returned. The return statement merely ends the function. The return value of a BASH function is stored in the variable $?.
File Information/Operations
ls		Listing of files. For bash, learn the options of -lisa, -r, -R.
	ls	Listing of files. For PowerShell, learn -f, -r, -filter,and -exclude
tree	tree	Graphically displays the directory structure of a drive or path.
cat	cat	List the contents of a file on the stdout
more	more	List the contents of a file on the stdout, pausing after each page
mkdir	mkdir	Creates a directory.
rmdir	rmdir	Deletes a folder if it is empty
pwd	pwd	print working directory
cd	cd	Change the current directory to the one given as argument.
pushd	pushd	Saves the current directory name on the stack, and then cd's the one given as argument.
popd	popd	Pop off the top-most name on the stack, and then cd to it
mv	mv	Moves or renames files. In PowerShell, check out the -force and -WhatIf flags. In BASH, check out the -f flag.
cp -r	cp -r	Copies files and directory trees recursively.
cp	cp	Copies files. In PowerShell, check out the -force and -WhatIf flags. In BASH, check out the -f flag.
rm	rm	Deletes a file. Check out the -r flag. In PowerShell, check out the -force and -WhatIf flags. In BASH, check out the -f flag.
cat	cat	show the contents of each file in sequence
more	more	pagination
rm	rm	Remove files
ln		Link (hard or soft) to an existing file.
	mklink	Link (hard or soft) to an existing file. Type cmd /c mklinkto use it in PowerShell
chmod	attrib	Change file permissions/attributes
	icacls	Displays or modifies access control lists (ACLs) of files
chown	icacls	Change ownership of a file. In PowerShell, multiple steps are necessary
umask		get/set the file mode creation mask; packed vector of bits controlling the initial permissions on a newly created file
du	measure	Disk space Used. In PowerShell, try gci . -r | measure -property length -sum
wc	Measure-Object	word count, etc.
od		Octal dump of file content. Almost always used with -x for hexadecimal dump
tr		Translate/substitute characters; useful in improving interoperability
	assoc	List associations of commands with extensions. Type cmd /c assoc to use it in PowerShell
file		Heuristically determine the type of file content
grep	select-string	Search for a string in a file's content. For now, learn it without regexp.
find	gci	Locate a file. By name, etc. For now, learn it without regexp.
which		Gives the full path name of a command
	where	Gives the full path name of a command.  Type cmd /c where to use it in PowerShell
diff	diff	List the differences between two text files
cmp, diff	compare, diff	show the differences between two files
	gci . -r | sort length -descending | select -first 10	get a list of the 10 largest files in the current directory (recursive)
vi	vim	A powerful text editor. For now, learn to edit simple text files with it.
kate, leafpad	notepad	Simple text editors.
emacs	emacs	A very powerful multi-purpose text editor. For now, learn to edit simple text files with it.
Processes
time	Measure-Command	times commands, etc.
ps	ps	shows current processes
	gps | sort ws | select -last 5	Get a list of the 5 processes using the most memory
	gsv | where {$_.Status -eq "Stopped"}	Get a list of stopped services
top		like ps, but with continuous updates
bg		place a STOPped process in the background
fg		bring a backgrounded process to foreground
kill	kill	kills a running program
ltrace		show lib calls made
strace		show sys calls made
System
man	man	show reference pages
set	set	set the values of shell variables
set	gv	get and show the values of shell variables
env	ls env:\	lists the current environment variables
$PATH	$env:path	the search path
links		WWW/News/Mail browser
sftp, filezilla	filezilla	transfer files securely to/from a remote machine
ssh, putty	sshclient, putty	remote login securely
w		who is on the system, and what they are doing
df	gdr	show mounted volumes, etc.