记录无法归类的小问题及解决方法
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Windows下转换的UTF-8文件通常为UTF-8 BOM, 文件的行首存在字符G，怎么查看和去除？
在vim中执行
:set nobomband:wq或在终端执行perl -pi~ -CSD -e 's/^\x{fffe}//' file执行
less -a file可以看有无特殊字符。 -
vim配置文件位置？
/etc/vimrc or ~/.vimrc -
查看端口对应的进程
lsof -Pnl +M -i4 -
网站不能访问或没有权限 （关闭防火墙）
#启动： systemctl start firewalld #关闭： systemctl stop firewalld #查看状态： systemctl status firewalld #开机禁用 ： systemctl disable firewalld #开机启用 ： systemctl enable firewalld firewall-cmd --zone=public --add-port=80/tcp --permanent （--permanent永久生效，没有此参数重启后失效） #重新载入 firewall-cmd --reload #查看 firewall-cmd --zone= public --query-port=80/tcp #删除 firewall-cmd --zone= public --remove-port=80/tcp --permanent -
关闭SELINUX
setenforce 0 # 临时 # 永久 vim /etc/sysconfig/selinux SELINUX=enforcing 改为 SELINUX=disabled 重启服务reboot -
查看端口是否通
telnet server_ip 25(25为端口号) -
fork: retry: Resource temporarily unavailable
修改最大允许的进程数和打开文件数
在文件
/etc/security/limits.conf中增加或修改如下文字# <*> 可替换为用户名 * soft nofile 65535 * hard nofile 65535 * soft nproc 65535 * hard nproc 65535如果是centos6，还需修改文件
/etc/security/limits.d/90-nproc.conf* soft nproc 102400 * hard nproc 102400修改完成后，重新登录服务器，运行
ulimit -a查看。 -
Centos6安装Mysql5.7
```bash
官网下载源码包
wget http://dev.mysql.com/get/mysql57-community-release-el6-7.noarch.rpm
rpm安装yum源
rpm -Uvh mysql57-community-release-el6-7.noarch.rpm
Mysql安装
yum install -y mysql-community-client mysql-community-server
Start mysql service
service mysqld start /etc/init.d/mysqld start
在日子/var/log/mysqld.log中会有root的密码信息
temporary password is generated for root@localhost: gaB1wd
查看并设置mysqld自启动
chkconfig –list | grep mysqld chkconfig mysqld on
配置mysql
mysql_secure_installation
# /tmp/mysql.sock # 获取 mysql.sock的位置 netstat -ln | grep mysql
* [install ref](https://segmentfault.com/a/1190000005820034)
* 启动错误InnoDB: The Auto-extending innodb_system data file './ibdata1' is of a different size 640 pages (rounded down to MB) than specified in the .cnf file: initial 768 pages, max 0 (relevant if non-zero) pages!))''
Add `innodb_data_file_path = ibdata1:10M:autoextend` to `/etc/my.cnf` `mysqld` block
OR
Remove `ib*` files in mysql datadir
* 启动错误 Fatal error: mysql.user table is damaged. Please run mysql_upgrade.
First, start your mysql without reading the user table: `/etc/init.d/mysqld start --skip-grant-tables`; Then run `mysql_upgrade` which should now run smoothly; Next stop mysqld: `killall mysqld`. Now you should be able to start up your mysql service normally again. [ref](https://stackoverflow.com/questions/36156475/mysqld-doesnt-start-after-brew-upgrade-from-5-6-to-5-7)
* Mysql datadir
Defined in file `/etc/my.conf` with `datadir=/mysql`.
```
# stop mysqld service
service mysqld stop
# change mysql datadir
## mkdir
mkdir -p /test2/mysql
chown mysql:mysql /test2/mysql
/bin/cp /var/lib/mysql/* /test2/mysql/
## change /etc/my.cnf
# datadir=/var/lib/mysql
datadir=/test2/mysql
#socket=/var/lib/mysql/mysql.sock
socket=/test2/mysql/mysql.sock
.
.
.
[client]
port=3306
socket=/test2/mysql/mysql.sock
## Change /etc/init.d/mysql
#get_mysql_option datadir "/var/lib/mysql" mysqld
get_mysql_option datadir "/test2/mysql" mysqld
# start mysqld service
service mysqld start
```
* Your password does not satisfy the current policy requirements
PASSWORD needs containing uppercase leters, lowercase letters, numbers and special characters.
Please refer [here](http://bbs.bestsdk.com/detail/762.html) to `SET GLOBAL validate_password_policy='LOW';`。
* DBD::mysql::st execute failed: The total number of locks exceeds the lock table size
Add "innodb_buffer_pool_size = 10G" to /etc/my.conf (default innodb buffer size is 128 M, change to some number larger).
Then restart mysqld service `/etc/init.d/mysqld restart`.
Check the value of `innodb_buffer_pool_size` using `show variables like 'innodb_buffer_pool_size';`.
6. centos安装pandoc，pandoc-citeproc
```bash
#make sure libgmp.so.10 in LD_LIBRARY_PATH
#locate libgmp.so.10
#Add path of libgmp.so.10 to file /etc/ld.so.conf
#ldconfig -v
# Install stack
curl -sSL https://get.haskellstack.org/ | sh
stack setup
# cable install cpphs
cabal install cpphs
#Clone and install
mkdir pandoc-build
cd pandoc-build
git clone https://github.com/jgm/pandoc-types
git clone https://github.com/jgm/texmath
git clone https://github.com/jgm/pandoc-citeproc
git clone https://github.com/jgm/pandoc
git clone https://github.com/jgm/cmark-hs
git clone https://github.com/jgm/zip-archive
cd pandoc
git submodule update --init
stack install --test --install-ghc --stack-yaml stack.full.yaml
# pandoc and pandoc-citeproc will be installed to /root/.local/bin
# add this directory to PATH
To pull in the latest changes, after you’ve done this and there have been changes in the repositories: Visit each repository in pandoc-build (pandoc-types, texmath, pandoc-citeproc, pandoc, zip-archive, cmark-hs) and do git pull. In the pandoc repo, also do git submodule update and stack install --test --stack-yaml stack.full.yaml.)
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添加用户并root权限
adduser username passwd username 赋予权限 # /etc/sudoers username All=(ALL) ALL # /etc/passwd -
Apache配置权限
# Modify config file to allow .htaccess # /etc/httpd/conf/httpd.conf <Directory "/var/www/html"> ------ #Add following line AllowOverride AuthConfig </Directory>Restart server
apachectl restart# In the folder which access wanted to be controlled # create .htaccess with following content # make sure .htpasswd_label not in same dir as .htaccess # require: can specify username; valid-user meaning all users in .htpasswd can have access AuthType Basic AuthName "Please contact administrator for more information!!!" AuthUserFile /dir/.htpasswd_label require valid-user #Generate
.htpasswd_labelwith commandhtpasswd -cmb /dir/.htpasswd_label username userpasswd. Apache下以.ht开头的文件不会被外部读取，安全性比较高。若出现500 EROOR，请查阅
/etc/httpd/logs/error_log根据具体信息解决。 -
权限问题
chgrp -R user_grp dir -
awk输出到文件
awk 'BEGIN{OFS=FS="\t";file="output"}{print $1 >file; print $2;}' input >output2 -
去除文件最后2行
head -n -2 file #notice -2 -
Perl程序内设置环境变量
$ENV{PATH} = "/MPATHB/soft/java8/jdk1.8.0_121/bin:$ENV{PATH}"; -
awk循环输出
awk '{for (i=1; i<=NF; i++) printf "%.3f %s", $$i, (i==NF?RS:FS)}' file -
Mariadb status and stop
systemctl status mariadb systemctl stop mariadb -
查看端口使用情况
netstat -a | grep '8080' lsof -i:8080 -
给文件夹而非文件增加可执行属性
The important thing to note here is that uppercase
Xacts differently to lowercasex. In manual we can read:The execute/search bits if the file is a directory or any of the execute/search bits are set in the original (unmodified) mode. In other words,
chmod u+Xon a file won’t set the execute bit; andg+Xwill only set it if it’s already set for the user.chmod -R u+rwX,g+rwX,go-rwx path or find /path/to/base/dir -type d -exec chmod 755 {} + find /path/to/base/dir -type f -exec chmod 644 {} + chmod 755 $(find /path/to/base/dir -type d) chmod 644 $(find /path/to/base/dir -type f) find /path/to/base/dir -type d -print0 | xargs -0 chmod 755 find /path/to/base/dir -type f -print0 | xargs -0 chmod 644 -
awk中执行系统命令 (注意引号的使用)
awk 'BEGIN{OFS=FS="\t"}{system("mv "$1".fq "$2".fq");}' 1 -
定义全局函数
# write in ~/.bash_profile abcdefg() { echo 'CT' } export -f abcdefg # source ~/.bash_profile # use in another program #!/bin/bash #set -x set -e set -u abcdefg -
输出到标准错误
(>&2 echo "I willbe output to STDERR")
- scp 和 rsync 非默认端口
scp -P remote_port_number local remote
rsync -av -e 'ssh -p remote_port_number' local remote
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find 使用
find . -name *.log -newer pca/2018-02-10.txt -size +0 -
zip -j file.zip file # 不包含路径
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用户操作
# 批量修改密码
cat <<END >user_pass
user1:pass1
user2:pass2
END
chpasswd <user_pass
# 用户增加组
usermod -a -G ehbio ct
# 新建用户
cat <<END >/tmp/${user}.create
${user}:${password}::${group}::/disk/${user}:/bin/bash
END
newusers </tmp/${user}.create
# 删除用户
userdel -r ${user}
- csplit
csplit --elide-empty-files --prefix=test test.fa '/^>/' "{*}"
- 取出文件倒数第二行
rev file | cut -f 2 | rev
# 扔掉倒数第二行
rev file | cut -f 2 --complement | rev
awk '{a=NF-1; print $a}' file
- 合并pdf
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/default -dNOPAUSE -dQUIET -dBATCH -dDetectDuplicateImages -dCompressFonts=true -r150 -sOutputFile=output.pdf input.pdf