linux shell 一些命令
https://stackoverflow.com/questions/918886/how-do-i-split-a-string-on-a-delimiter-in-bash
wc:
https://unix.stackexchange.com/questions/51945/why-are-wc-m-and-wc-c-different
https://stackoverflow.com/questions/31563546/how-to-use-shell-to-count-chinese-characters-in-file-encoded-in-utf-8
How do I use shell variables in an awk script?
https://stackoverflow.com/questions/19075671/how-do-i-use-shell-variables-in-an-awk-script
https://unix.stackexchange.com/questions/84063/passing-a-variable-to-sed
https://stackoverflow.com/questions/7006910/shell-variables-in-sed-script