professor.db中每個檔案塊記錄了一位教授的資訊,由三行組成:第1行是姓名,第2行是學校名,第3行是學校所處的城市和國家.如果需要根據姓名對檔案塊進行排序,僅使用sort命令是難以實現的,我們通過結合使用sort和awk來實現這一功能:

cat professor.db:

J Luo

Southeast University
Nanjing,China

Y Zhang
Victory University
Melbourne, Australia

D Hou
Beijing University
Beijing,China

B Liu
Shanghai Jiaotong University
Shanghai,China

C Lin
University of Toronto
Toronto,Canada

=================================================

cat PROFESSOR.db | awk -v RS="" '{gsub("\n","@");print}'
J [email protected] [email protected],China
Y [email protected] [email protected], Australia
D [email protected] [email protected],China
B [email protected] Jiaotong Universit[email protected],China
C [email protected]

of [email protected],Canada

===================================================
cat PROFESSOR.db | awk -v RS="" '{gsub("\n","@");print}' | sort
B [email protected] Jiaotong [email protected],China
C [email protected] of [email protected],Canada
D [email protected] [email protected]

,China
J [email protected] [email protected],China
Y [email protected] [email protected], Australia
=====================================================
cat PROFESSOR.db | awk -v RS="" '{gsub("\n","@");print}' | sort |awk -v ORS="\n\n" '{gsub("@","\n");print}'
B Liu
Shanghai Jiaotong University
Shanghai,China

C Lin
University of Toronto
Toronto,Canada

D Hou
Beijing University
Beijing,China

J Luo
Southeast University
Nanjing,China

Y Zhang
Victory University
Melbourne, Australia