How do a find data in one file, search for it in another file and if not found, write a custom message to another file

in file if.txt, starting on 2nd line of file, data formatted follows:

ah10551,a10551,cn=a10551,a10551@qts.com
ah10600,a10600,cn=a10600,a10600@qts.com
ah10608,a10608,cn=a10608,a10608@qts.com

in file sf.txt, data formatted follows:

2011-02-16 17:26:44 sid acme\ah10551 added sid history of qts\a10551
2011-02-16 17:26:44 sid acme\ah10244 added sid history of qts\a10244
2011-02-16 17:26:45 sid acme\ah10425 added sid history of qts\a10425

please provide suggestions on how following:

1. in if.txt file, read first field first ',' , store in variable called $if1

2. in sf.txt file, search for the value stored in $if1 , if found, ignore.  if not found, write custom message in another file such as: $if1 sidhistory not migrated.

these files wont large.  im trying build 'exception file' of items in if.txt file not occurring in sf.txt file.

thanks in advance ideas.

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mtv99

many ways that... here's one... (using example data)

[array]$if1=@()
gc d:\if.txt | select -skip 1 | %{$if1+=($_ -replace '(\w\d),.+','$1')}
$sf=[system.io.file]::readalltext("d:\sf.txt")
$if1 | %{if(!($sf.contains($_))){write-host match not found $_}}

match not found ah10600
match not found ah10608

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just humble sysadmin

Windows Server  >  Windows PowerShell