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本系列的awk教程中，将大量使用到如下示例文件a.txt。
ID name gender age email phone
1 Bob male 28 [email protected] 18023394012
2 Alice female 24 [email protected] 18084925203
3 Tony male 21 [email protected] 17048792503
4 Kevin male 21 [email protected] 17023929033
5 Alex male 18 [email protected] 18185904230
6 Andy female 22 [email protected] 18923902352
7 Jerry female 25 [email protected] 18785234906
8 Peter male 20 [email protected] 17729348758
9 Steven female 23 [email protected] 15947893212
10 Bruce female 27 [email protected] 13942943905