grep_shell三剑客

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egrep_扩展grep

扩展grep(grep -E 或者 egrep)

egrep ‘NW|EA‘ testfile

northwest NW Charles Main 3.0 .98 3 34
eastern EA TB Savage 4.4 .84 5 20

原文：https://www.cnblogs.com/kingcs/p/14586441.html