Vista - Replace

Hej Powershell team.

In gui-help replace it can be defined as - a specified number of
times.
But how should i do, if i only will change the first space and not the
other space
in the following example ???

${C:\powerstart.txt} -replace ' ',';' > C:\powerstart1.txt

I need a real reference manual !!
--------------------------------------------------------------------

Replace

Definition: Returns a string in which a specified substring has been
replaced
with another substring a specified number of times.

$a = "bxnxnx"
$a = $a -replace("x","a")

Regards
Torben Brønsholm
Denmark

The String.Replace constructor takes only 2 parameters :

PS C:\Scripts> "bxnxnx" | gm rep*


TypeName: System.String

Name MemberType Definition
---- ---------- ----------
Replace Method System.String Replace(Char oldChar, Char newChar), System.String
Replace(String oldValue, String newValue)


Use the Regex.Replace Method instead (http://msdn2.microsoft.com/en-us/lib...31(VS.71).aspx

This will replace only the first and second occurrences of "x" in "bxnxnx"

PS > $r=[regex]'x';
PS > $r.Replace("bxnxnx","a",2)
bananx






Shay
http://scriptolog.blogspot.com

The same applies for the -Replace operator

PS C:\Scripts> "bxnxnx" -Replace("x","a",2)
The -replace operator only permits 2 elements on the right-hand side, not 3.
At line:1 char:18
+ "bxnxnx" -Replace( <<<< "x","a",2)

So, regex is your best friend in this case.

Shay
http://scriptolog.blogspot.com


PS>> $r=[regex]'x';
PS>> $r.Replace("bxnxnx","a",2)

BTW, to replace all occurrences of "x" use a negative number (or just omit
the third argument)

$r=[regex]'x';
$r.Replace("bxnxnx","a",-1)
banana

Shay
http://scriptolog.blogspot.com


PS>> $r=[regex]'x';
PS>> $r.Replace("bxnxnx","a",2)

> PS > $r=[regex]'x';

And this will do a space:
$r=[regex]' '

In some cases, (much) more complex regular expressions are required to
match things just the way you want it.

Marco

The replace operator supports regex.
To just replace the first space use a regex that only selects the first
space. i.e. '^ '
e.g. $a -replace '^ ',';' | output

<tb@xxxxxx> wrote in message
news:1192269312.197948.307570@xxxxxx
Hej Powershell team.

In gui-help replace it can be defined as - a specified number of
times.
But how should i do, if i only will change the first space and not the
other space
in the following example ???

${C:\powerstart.txt} -replace ' ',';' > C:\powerstart1.txt

I need a real reference manual !!
--------------------------------------------------------------------

Replace

Definition: Returns a string in which a specified substring has been
replaced
with another substring a specified number of times.

$a = "bxnxnx"
$a = $a -replace("x","a")

Regards
Torben Brønsholm
Denmark

Here are two match patterns that create three matched groups. The second group is the first space found. The replace pattern consists of the first group, the character that will replace the second group and the third group. Try it:

$pattern1 = '(.*?)( )(.*)'
$pattern2 = '([^ ]*?)( )(.*)'

" 1 2 3 " -replace $pattern1, '$1;$3'
"1 2 3 " -replace $pattern1, '$1;$3'
"12 3 " -replace $pattern1, '$1;$3'
"123 " -replace $pattern1, '$1;$3'

" 1 2 3 " -replace $pattern2, '$1;$3'
"1 2 3 " -replace $pattern2, '$1;$3'
"12 3 " -replace $pattern2, '$1;$3'
"123 " -replace $pattern2, '$1;$3'

--
Kiron

I think that would be a good suggestion to put up in Connect. Maybe there is still time left to include a third element, the repetition element default to -1, in the -replace operator for v2.

--
Kiron

Expresso (http://www.ultrapico.com/Expresso.htm) is a great tool for working
with regular expressions. It can explain existing regular expressions or it
can help you develop your own.

regards

Michiel

"tb@xxxxxx" wrote: