If [“X” == “X” ]; then echo“1” ; echo“2” ; echo“3” ; fi If [“X” == “Y” ]; then echo“1” ; echo“2” ; echo“3” ; fi The statements of the first “if” condition are presented in the output on the following lines when we run the script, as you can...
if condition1;then condition1为真时执行的代码 elif condition2;then condition2为真时执行的代码 elif condition3;then condition3为真时执行的代码 ... elif condition10;then condition10为真时执行的代码 else 条件都为假时执行的代码 fi#多分支的if语句elif可以出现n次; 注意:即便多个分支条件可能同时都能...
Upon execution, the program has started to output the string “hello” without stopping as per the following output. If you want to exit this one-line loop, press “Ctrl+X” on the shell. Now, check out the output in the following screenshot: Example 02: Let’s look at another one-l...
echo"FILE EXTENSION = ${EXTENSION}"echo"SEARCH PATH = ${SEARCHPATH}"echo"DEFAULT = ${DEFAULT}"echo"Number files in SEARCH PATH with EXTENSION:"$(ls-1"${SEARCHPATH}"/*."${EXTENSION}" | wc -l) if [[ -n $1 ]]; then echo "The non option arguments are:" $@ fi EOF chmod +x...
You can use this if .. elif.. if , if you want to select one of many blocks of code to execute. It checks expression 1, if it is true executes statement 1,2. If expression1 is false, it checks expression2, and if all the expression is false, then it enters into else block and...
f()if true; then echo "$1"; fi f()for i in "$@"; do echo "$i"; done if语法更短 # One line # Note: The 3rd statement may run when the 1st is true [[ $var == hello ]] && echo hi || echo bye [[ $var == hello ]] && { echo hi; echo there; } || echo bye ...
Here, we list some basic bash syntax with a brief explanation. It is a good starting point if you are a beginner.
If no commands are executed, the exit status is 0. An attempt is first made to open the file in the current directory, and, if no file is found, then the shell searches the directories in PATH for the script. INVOCATION A login shell is one whose first character of argument zero is ...
Thermdircommand deletes (removes) a directory, but only if it's empty. If it's not empty, you get a warning instead. Fortunately, you can use thermcommand to delete directories that aren't empty in combination with the-r(recursive) flag. The command would then look like so,rm -r. ...
If, for some reason,n-uninstalldoesn't work, do the following: Remove theN_PREFIXenvironment-variable definition and associatedPATHmodification from your shell's initialization file. Remove the directory thatN_PREFIXpoints to: Be sure that that directory contains no content unrelated tonthat you may...