When writing Bash scripts you will often need to compare two strings to check if they are equal or not. Two strings are equal when they have the same length and contain the same sequence of characters. This tutorial describes how to compare strings in Bash....
/bin/bash # Script to do numeric comparisons var1=10 var2=20 if [ $var2 -gt $var1 ] then echo "$var2 is greater than $var1" fi # Second comparison If [ $var1 -gt 30] then echo "$var is greater than 30" else echo "$var1 is less than 30" fi Compare Strings 我们可能还...
/bin/bash str1="hello" str2="world" function compare_strings { if [ "$1" = "$2" ]; then echo "两个字符串相等" else echo "两个字符串不相等" fi } compare_strings "$str1" "$str2" ``` 在这个例子中,我们定义了一个名为`compare_strings`的函数来完成字符串比较操作。通过调用这个函...
/bin/bash # Script to do numeric comparisons var1=10 var2=20 if [ $var2 -gt $var1 ] then echo "$var2 is greater than $var1" fi # Second comparison If [ $var1 -gt 30] then echo "$var is greater than 30" else echo "$var1 is less than 30" fi Compare Strings 我们可能还...
Compare Strings 我们可能还需要比较两个或多个字符串,比较字符串可能有点棘手。对于字符串的比较,使用的参数如下所示: var1 = var2 检查 var1 是否与 var2 相同 var1 != var2 检查 var1 是否与 var2 不同 var1 < var2 检查 var1 是否小于 var2 ...
PTXdist是一个固件镜像构建工具,是 Pengutronix 在 2001 年开发的一个构建系统。采用了 Linux 内核中的配置系统 Kconfig 来选择和配置每个包,规则集合则基于 GNU Make 和 Bash。 OpenWRT OpenWRT是一个针对嵌入式设备的 Linux 操作系统。OpenWrt 不是一个单一且不可更改的固件,而是提供了具有软件包...
Ubuntu is the modern, open source operating system on Linux for the enterprise server, desktop, cloud, and IoT.
The shell can store temporary variables, called shell variables, containing the values of text strings. Shell variables are very useful for keeping track of values in scripts, and some shell variables control the way the shell behaves. (For example, the bash shell reads the PS1 variable before...
Know your shell: Bash, zsh, fish? Different shells have unique features. Pick the one that suits your needs the best.Master the core utils: ls, cat, grep, sed, awk, etc form the core of a Linux toolkit.Stick with pipelines: Avoid excessive uses of temporary files. Pipe programs ...
工欲善其事必先利其器,要想分析清楚linux服务器中的各类问题,比如性能问题,服务程序的bug,那么必须对该系统下的分析工具有一定的了解,本文对当前的主流cpu,内存,网络,io以及各种debug分析工具(blktrace,perf,systemtap)做了个简单总结。 注:学无止境,故需持续更新 ...