Need a regex to find the word "ERROR:", but not match "ERROR: Opening Local File"
As @spikey_richie says, you need negative lookahead:
ERROR: (?!Opening local file)
Basically, instead of specifying what you're looking for, you specify what you don't want, and wrap that inside (?!
and )
.
Demo
this seems to do what you want - it uses the way that PoSh can apply a regex match to an entire collection. [grin]
what it does ...
- creates a sample data set
when ready to do this for real, replace the entire#region/#endregion
block with aGet-Content
call. - sets the wanted pattern
- sets the unwanted pattern
- uses chained regex calls to exclude the unwanted and then to include the wanted
- assigns that to the
$Result
collection - displays that on screen
the code ...
#region >>> fake reading in a text file
# in real life, use Get-Content
$InStuff = @'
ERROR: Writing local file (I want to be alerted to this)
ERROR: Opening local file (I do not want to be alerted to this)
INFO: Some other thing
ERROR: Yet another thing
INFO: A thing that is wanted
WARNING: Something that may be wanted
'@ -split [System.Environment]::NewLine
#endregion >>> fake reading in a text file
$TargetPattern = 'error:'
$NotWantedPattern = ': opening local file'
$Result = $InStuff -notmatch $NotWantedPattern -match $TargetPattern
$Result
output ...
ERROR: Writing local file (I want to be alerted to this)
ERROR: Yet another thing
Something like that should work too : Demo
$MyString = @'
ERROR: Writing local file (I want to be alerted to this)
ERROR: Opening local file (I don't want to be alerted to this)
INFO: Some other thing
ERROR: Yet another thing
INFO: A thing that is wanted
WARNING: NOT a not-wanted thing
'@ -split [System.Environment]::NewLine
$pattern = 'ERROR: (?!Opening local file).+'
$MyString | %{ [regex]::matches($_,$pattern) } | %{ $_.Groups[0].Value }