Trim all white-space from string and truncate spacesThis is an alternative to sed, awk, perl and other tools. The function below works by abusing word splitting to create a new string without leading/trailing white-space and with truncated spaces....
Let’s look at another option, “-z”, used so far in Bash to check for the empty string. The code has been started with Bash support, and we have initialized a string variable “v” with the value “Hello” in it. Then, we started the “if-else” statement to check whether the ...
In addition to logical flags there are also logical operators. One of the most useful logical operators is the regex match operator=~. The regex match operator compares a string to a regular expression and if the string is a match for the regex then the expression is equivalent totrue, othe...
if [[ $var != sub_string* ]]; then printf '%s\n' "var does not start with sub_string." fiCheck if string ends with sub-stringif [[ $var == *sub_string ]]; then printf '%s\n' "var ends with sub_string." fi # Inverse (var does not end with sub_string). if [[ $var...
How to check if a string is in an array? How to use the Bash ternary operator? How to negate an if condition in a Bash if statement? (if not command or if not equal) How to use the BASH_REMATCH variable with the Regular Expression Operator =~?
在bash中,如果被转义,单引号可以包含在$'string'形式的单词中。此外,第二章对printf的描述中列出的转义序列被替换为它们所代表的字符: $ echo $'\'line1\'\n\'line2\'' 'line1' 'line2' 引用的参数可以包含文字换行符: $ sa "Argument containing `> a newline"` `:Argument containing` `a newli...
! expression: True if the expression is false. -n string: True if the length of the string is greater than zero. -z string: True if the length of the string is zero. That is, it's an empty string. string1 = string2: True if string1 is the same as string2. ...
I would like to do something if the output of a shell script contains the string "Caddy 2 serving static files on :2015". This is what I have so far but the beach ball is just spinning. It seems it is because of the last command in my bash script which starts a server. There is...
‘test’: Check file types and compare values man test(获取帮助) test的判断表达式分为4类 string integer expression file testexits with the status determined by EXPRESSION. Placing the EXPRESSION between square brackets ([and]) is the same as testing the EXPRESSION withtest. ...
等待enter命令既然你在推doSqoop做背景工作&，唯一限制脚本执行时间的是sleep 0.5不管花多长时间check...