Sure. 

m[
    ^           # From the start of the record
    (           # capture
        [^|]+   # everything that is not a pipe char
    ) 
    \|          # upto but excluding the first pipe char
]x

[download]

In essence, grab the first field of a pipe delimited record into $1.

Assumes that that field doesn't contain an escaped or quoted pipe character. Which is the normal case.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
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In reply to Re^3: how to find differences between two huge files by BrowserUk
in thread how to find differences between two huge files by sayeevamsi

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