Under Logical operators, Bash provides logical OR operator that performs boolean OR operation. Bash boolean OR operator takes two operands and returns true if any of the operands is true, else it returns false. OR logical operator combines two or more simple or compound conditions and forms a c...
When used with [[, the < and > operators sort lexicographically using the current locale. The test command sorts using ASCII ordering. 即,条件表达式被[[复合命令、test内置命令、和[内置命令用来判断文件属性、进行字符串比较、进行算术比较。 在CONDITIONAL EXPRESSIONS小节中,列举了很多条件表达式,对常用的...
‘Else if’, or ‘elif’ as it’s often written in bash, is a fundamental part of conditional statements in bash scripting. It allows your scripts to check multiple conditions and execute different blocks of code based on the outcomes of these checks. Syntax of ‘Else If’ The basic synta...
are performed. Conditional operators such as -f must be unquoted to be recognized as primaries. When used with [[, the < and > operators sort lexicographically using the current locale. See the description of the test builtin command (section SHELL BUILTIN COMMANDS below) for the handling of...
Conditional operators such as -f must be unquoted to be recognized as primaries.When used with [[, the < and > operators sort lexicographically using the current locale.See the description of the test builtin command (in the section "Shell Builtin Commands" below) for the handling of ...
Returns a status of0or1depending on the evaluation of the conditional expression EXPRESSION. Expressions are composed of the same primaries used by the `test'builtin, and may be combined using the following operators:( EXPRESSION ) Returns the value of EXPRESSION! EXPRESSION TrueifEXPRESSION isfals...
Evaluate conditional expression. Exits with a status of 0 (true) or 1 (false) depending on the evaluation of EXPR. The behavior of test depends on the number of arguments. Read the bash manual page for the complete specification. String operators: ...
If the first number is less than or equal to the second, the condition evaluates to true; otherwise, it evaluates to false. The-leoperator is commonly used in conditional statements likeifandwhile. Examples of-le(Less Than or Equal To) Operator ...
Conditional execution uses two operators: AND (&&) and OR (||) which you can use to control what command get executed based on their exit status. Conditional expressions are always in double brackets ([[ ]]). They have an exit status of 0 if they contain a true assertion or 1 if the...
Pay special attention to space. There must be space between the opening and closing brackets and the conditions. Similarly, space must be before and after the conditional operators (-le, == etc). Here's what it shows when I run the script: ...