| 格式 | 说明 |
|---|---|
| ${string: start :length} | 从 string 字符串的左边第 start 个字符开始，向右截取 length 个字符 |
| ${string: start} | 从 string 字符串的左边第 start 个字符开始截取，直到最后 |
| ${string: 0-start :length} | 从 string 字符串的右边第 start 个字符开始，向右截取 length 个字符 |
| ${string: 0-start} | 从 string 字符串的右边第 start 个字符开始截取，直到最后 |
| $ |
FROM centos:7
ENV container docker
RUN (cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == \
systemd-tmpfiles-setup.service ] || rm -f $i; done); \
rm -f /lib/systemd/system/multi-user.target.wants/*;\
rm -f /etc/systemd/syg/^$/d
map {lhs} {rhs}
Map the key sequence {lhs} to {rhs} for the modes where the map command applies. The result, including
{rhs}, is then further scanned for mappings. This allows for nested and recursive use of mappings.
example : map <M-n> :tabnextsha512sum filename
$ sha512sum ls
ef73136452875c4cae5c6b43117c601ec679f027a4ff1c285d477ab6a8950edb9f8da0822a57b1c0eb719d563cb2033765cdf6c949e9df073fbf7772bf5fad71 ls
$ sha512sum ls > ls.sha512
$ sha512sum -c ls.sha512
ls: OK
dmesg | egrep -i -B100 'killed process'
或: egrep -i 'killed process' /var/log/messages egrep -i -r 'killed process' /var/log
或: journalctl -xb | egrep -i 'killed process'
切换到root或者使用sudo 打开/etc/sudoers 添加一行：yourname ALL=(ALL) NOPASSWD: ALL