Issue
I have a extremely large text file of size 250 GB that’s given to us by a vendor. They also give us a control file that is supposed to have the number of lines in the large file. Sometimes there is a mismatch.
How do I count lines in Powershell? I tried this command and it ran for more than half hour and was not done yet.
Get-content C:\test.txt | Measure-Object –Line
(gc C:\test.txt | Measure-object | select count).count
Any help is appreciated
Thanks
MR
Solution
If performance matters, avoid the use of cmdlets and the pipeline; use switch -File
:
$count = 0
switch -File C:\test.txt { default { ++$count } }
switch -File
enumerates the lines of the specified file; condition default
matches any line.
To give a sense of the performance difference:
# Create a sample file with 100,000 lines.
1..1e5 > tmp.txt
# Warm up the file cache
foreach ($line in [IO.File]::ReadLines("$pwd/tmp.txt")) { }
(Measure-Command { (Get-Content tmp.txt | Measure-Object).Count }).TotalSeconds
(Measure-Command { $count = 0; switch -File tmp.txt { default { ++$count } } }).TotalSeconds
Sample results from my Windows 10 / PSv5.1 machine:
1.3081307 # Get-Content + Measure-Object
0.1097513 # switch -File
That is, on my machine the switch -File
command was about 12 times faster.
Answered By – mklement0
Answer Checked By – David Goodson (BugsFixing Volunteer)