#!/bin/bash #: Description : print formatted sales report ## Build a long string of equals signs divider=== divider=$divider$divider ## Format strings for printf header="\n %-10s %11s %8s %10s\n" format=" %-10s %11.2f %8d %10.2f\n" ## Width of divider totalwidth=44 ## Pri...
[student@studentvm1 testdir]$ X=1 ; if [ $X -eq 1 ] ; then echo "X equals 1" ; else echo "X does not equal 1" ; fi X equals 1 [student@studentvm1 testdir]$ X=0 ; if [ $X -eq 1 ] ; then echo "X equals 1" ; else echo "X does not equal 1" ; fi X does n...
You can assign data to a variable using the equals sign (=). The data you store in a variable can either be a string or a number. Let’s create a variable now on the command line: chapter_number=5 The variable name is on the left hand side of the equals sign, and the data whic...
bash 中的条件语句,基础就是 Test 。...case case 其实就是我们熟悉的那个 swich ,但语法形式上有很大的不同。...循环 bash 中有 for 和 while 两种常见的循环体,我们应该都很熟悉。 for 直接上实例,批量修改文件名。...; done 语法其实很明朗: for variable [in words]; do commands done do 可以另...
if 先来个实例: x=5; if [ $x = 5 ]; then echo 'x equals 5...中的条件语句, Test 是核心,if 和 case 熟悉语法即可。...循环 bash 中有 for 和 while 两种常见的循环体,我们应该都很熟悉。 for 直接上实例,批量修改文件名。...; done 语法其实很明朗: for variable [in words]; do comman...
Chanix-LGdeMacBook-Pro:shell_test chanix$ echo $@ -h 44. = 等号 等号(Equals)。 \1. 赋值操作,给变量赋值,在等号两侧禁止有空格; \2. 在比较测试中作为比较符出现,这里要注意,如果在[]中括号中作为比较出现,需要有空格符在等号左右两侧,如 [ $a==$b ]。
TestFile1 does not exist or is empty. 现在创建一个空文件用来测试: [student@studentvm1 testdir]$ File="TestFile1" ; touch $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ; fi ...
TestFile1 does not exist or is empty. 现在创建一个空文件用来测试: [student@studentvm1 testdir]$ File="TestFile1" ; touch $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ; fi ...
test "this string" = "that string" test 1 = 001 test 1 -eq 001 In each case, we usetheechocommandto print the return code of the last command. Zero means true, one means false. Using the equals sign "=" gives us a false response comparing 1 to 001. That's correct, because the...
In this case, the expression is slightly different, instead of typing true or false, thestdoutvariable is printed using$?. Check if strings are not equals The!=operator checks if String1 is not equal to String2. If the two strings are not equal, then it returns 0. If two strings are...