Works for me:
perl -E 'say q{@SRR254172.1 ILLUMINA-20A1B2_0004_FC6282EAAXX:6:1:1433:
+941 length=160}
             =~ /^@\S+\s+ILLUMINA\S+:(\d+):(\d+):(\d+):(\d+)\s+length=
+160/'
611433941

[download]
Maybe your input line contains some invisible characters somewhere?

In reply to Re: trouble with @ in a regular expression by choroba
in thread trouble with @ in a regular expression by efoss

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