“Shell基础”的版本间的差异
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| − | == | + | |
| + | [[Shell札记]] | ||
| + | ==IF条件判断，判断条件== | ||
| + | |||
| + | <pre> | ||
| + | |||
| + | 1 字符串判断 | ||
| + | |||
| + | str1 = str2 当两个串有相同内容、长度时为真 | ||
| + | str1 != str2 当串str1和str2不等时为真 | ||
| + | -n str1 当串的长度大于0时为真(串非空) | ||
| + | -z str1 当串的长度为0时为真(空串) | ||
| + | str1 当串str1为非空时为真 | ||
| + | |||
| + | 2 数字的判断 | ||
| + | |||
| + | int1 -eq int2 两数相等为真 | ||
| + | int1 -ne int2 两数不等为真 | ||
| + | int1 -gt int2 int1大于int2为真 | ||
| + | int1 -ge int2 int1大于等于int2为真 | ||
| + | int1 -lt int2 int1小于int2为真 | ||
| + | int1 -le int2 int1小于等于int2为真 | ||
| + | |||
| + | 3 文件的判断 | ||
| + | |||
| + | -r file 用户可读为真 | ||
| + | -w file 用户可写为真 | ||
| + | -x file 用户可执行为真 | ||
| + | -f file 文件为正规文件为真 | ||
| + | -d file 文件为目录为真 | ||
| + | -c file 文件为字符特殊文件为真 | ||
| + | -b file 文件为块特殊文件为真 | ||
| + | -s file 文件大小非0时为真 | ||
| + | -t file 当文件描述符(默认为1)指定的设备为终端时为真 | ||
| + | |||
| + | 3 复杂逻辑判断 | ||
| + | |||
| + | -a 与 | ||
| + | -o 或 | ||
| + | ! 非 | ||
| + | |||
| + | </pre> | ||
| + | [https://blog.csdn.net/ithomer/article/details/5904632 SHELL学习笔记----IF条件判断，判断条件] | ||
| + | |||
| + | |||
| + | =避免shell脚本被同时运行多次= | ||
| + | |||
| + | == 利用$0 排除自身== | ||
| + | <pre> | ||
| + | #!/bin/bash | ||
| + | root@evan-ThinkPad-Edge:~# cat /home/evan/tunnel | ||
| + | CPID=$$ #$$ 是脚本运行的当前进程ID号 | ||
| + | RUN="`ps -ef | grep "$0" | grep -v "grep" | grep -v "$CPID" | wc -l`" #$0 是脚本本身的名字 | ||
| + | [ "$RUN" -gt 1 ] && exit | ||
| + | ssh -i /home/evan/.ssh/id_rsa -p 22 -qtfnN -D 7070 [email protected] | ||
| + | |||
| + | |||
| + | </pre> | ||
| + | |||
| + | ==lockfile == | ||
| + | <pre> | ||
| + | LOCK_FILE="/tmp/my.lock" | ||
| + | if [[ -e $LOCK_FILE ]] ; then | ||
| + | echo "re-entry, exiting" | ||
| + | exit 1 | ||
| + | fi | ||
| + | |||
| + | ### Placing lock file | ||
| + | touch $LOCK_FILE | ||
| + | |||
| + | 你要写的代码 | ||
| + | |||
| + | ### Removing lock | ||
| + | rm -f $LOCK_FILE | ||
| + | </pre> | ||
| + | |||
| + | [https://blog.csdn.net/timchen525/article/details/76407605?utm_medium=distribute.pc_relevant.none-task-blog-2~default~baidujs_title~default-0.no_search_link&spm=1001.2101.3001.4242.1 Linux中如何防止一个Shell脚本被重复执行？] | ||
| + | |||
| + | [https://blog.csdn.net/sg656720274/article/details/73604551 如何避免shell脚本被同时运行多次] | ||
| + | |||
| + | [https://www.geek-share.com/detail/2632983934.html Shell脚本避免重复执行的方法 ] | ||
| + | |||
| + | [https://blog.51cto.com/lavasoft/243360 防止同一个Java应用重复启动的shell脚本] | ||
| + | |||
| + | =shell脚本特殊符号= | ||
| + | [https://www.cnblogs.com/xuxm2007/archive/2011/10/20/2218846.html shell脚本中一些特殊符号] | ||
| + | |||
| + | = MySQL backup shell script = | ||
| + | https://fedingo.com/shell-script-to-backup-mysql-database/ | ||
| + | |||
| + | https://www.fosstechnix.com/shell-script-for-mysql-database-backup/ | ||
| + | |||
| + | https://gist.github.com/lon-io/9067f746cd8cce10af4c52179c7e9b7e | ||
| + | |||
| + | https://orahow.com/linux-shell-script-for-mysql-database-backup/ | ||
| + | |||
| + | = shell规范= | ||
| + | |||
| + | https://www.shellcheck.net/ | ||
| + | |||
| + | [https://chegva.com/3977.html Shell编程规范实践指南] | ||
| + | |||
| + | [https://www.cnblogs.com/thatsit/p/shell-jiao-ben-shu-xie-gui-fan.html Shell脚本书写规范] | ||
| + | |||
| + | [https://www.iterdaily.com/post/shell-script-flavor/ shell书写规范建议] | ||
| + | |||
| + | [https://blog.csdn.net/lihonghai2392/article/details/77915439 shell脚本编写规范（超实用）] | ||
=see also= | =see also= | ||
| + | |||
| + | [https://blog.csdn.net/qq_45019159/article/details/104258887 Linux运维处理及监控脚本] | ||
| + | |||
| + | |||
| + | [https://www.centoschina.cn/course/introduction/9527.html CentOS下查看cpu，内存，硬盘等硬件信息的方法 ] | ||
| + | |||
| + | [https://blog.csdn.net/cd15109139570/article/details/80316911 linux系统中的shell脚本||脚本常用的命令] | ||
| + | |||
| + | [https://blog.csdn.net/weixin_39887925/article/details/116693709 linux运维脚本开发工具,送给运维人员的8个编写脚本的建议] | ||
[https://blog.csdn.net/u014285882/article/details/40679701 shell循环loop] | [https://blog.csdn.net/u014285882/article/details/40679701 shell循环loop] | ||
[[category:shell]] | [[category:shell]] | ||
2022年2月18日 (五) 02:58的版本
目录
IF条件判断，判断条件
1 字符串判断 str1 = str2 当两个串有相同内容、长度时为真 str1 != str2 当串str1和str2不等时为真 -n str1 当串的长度大于0时为真(串非空) -z str1 当串的长度为0时为真(空串) str1 当串str1为非空时为真 2 数字的判断 int1 -eq int2 两数相等为真 int1 -ne int2 两数不等为真 int1 -gt int2 int1大于int2为真 int1 -ge int2 int1大于等于int2为真 int1 -lt int2 int1小于int2为真 int1 -le int2 int1小于等于int2为真 3 文件的判断 -r file 用户可读为真 -w file 用户可写为真 -x file 用户可执行为真 -f file 文件为正规文件为真 -d file 文件为目录为真 -c file 文件为字符特殊文件为真 -b file 文件为块特殊文件为真 -s file 文件大小非0时为真 -t file 当文件描述符(默认为1)指定的设备为终端时为真 3 复杂逻辑判断 -a 与 -o 或 ! 非
避免shell脚本被同时运行多次
利用$0 排除自身
#!/bin/bash root@evan-ThinkPad-Edge:~# cat /home/evan/tunnel CPID=$$ #$$ 是脚本运行的当前进程ID号 RUN="`ps -ef | grep "$0" | grep -v "grep" | grep -v "$CPID" | wc -l`" #$0 是脚本本身的名字 [ "$RUN" -gt 1 ] && exit ssh -i /home/evan/.ssh/id_rsa -p 22 -qtfnN -D 7070 [email protected]
lockfile
LOCK_FILE="/tmp/my.lock" if [[ -e $LOCK_FILE ]] ; then echo "re-entry, exiting" exit 1 fi ### Placing lock file touch $LOCK_FILE 你要写的代码 ### Removing lock rm -f $LOCK_FILE
shell脚本特殊符号
MySQL backup shell script
https://fedingo.com/shell-script-to-backup-mysql-database/
https://www.fosstechnix.com/shell-script-for-mysql-database-backup/
https://gist.github.com/lon-io/9067f746cd8cce10af4c52179c7e9b7e
https://orahow.com/linux-shell-script-for-mysql-database-backup/
