（1）getline从交互式的用户输入中\c中获取内容；
# awk 'BEGIN {system("echo \"Input your name:\"");getline d;print "\nYour name is",d"!\n"}'
Input your name:
berry
Your name is berry!
# awk 'BEGIN {system(" echo \"Input your name:\\c\" ");getline d;print "\nYour name is",d"!\n"}'
Input your name:berry
Your name is berry!
（2）getline从文件中获取内容；
# awk -F":" 'BEGIN{while(getline < "/etc/passwd" >0){if($1~"sy"){print $1}}}'
sys
sync
syslog
（3）从命令输出中获取；
# awk 'BEGIN{"date" | getline d; print d}'
Sun Jan 1 22:37:50 CST 2017