int indexOf(String str) Returns the index within this string of the first occurrence of the specified substring. if (str.indexOf(sub) >= 0) { // do something } 使用String.matches方法判断是否包含子串,注意正则表达式元字符的转义 boolean matches(String regex) Tells whether or not this string ...
Here, we used theifconditional statement for matching a pre-defined stringWelcome to Baeldung. Next, we used the regex pattern[A-Z]with the=~operator. This operator checks if the string on its left side matches the pattern on the right. ...
_repeat() { #@ USAGE: _repeat string number _REPEAT=$1 while (( ${#_REPEAT} < $2 )) ## Loop until string exceeds desired length do _REPEAT=$_REPEAT$_REPEAT$_REPEAT ## 3 seems to be the optimum number done _REPEAT=${_REPEAT:0:$2} ## Trim to desired length } repeat() { ...
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...
string is null -n string is not null Regular Expressions Regular expressions are shortened as ‘regexp' or ‘regex'. They are strings of characters that define a search pattern. It can be used as a search or search & replace operation. Expressions Explanation . Matches any single character....
‘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. ...
Use regex on a stringThe result of bash's regex matching can be used to replace sed for a large number of use-cases.CAVEAT: This is one of the few platform dependent bash features. bash will use whatever regex engine is installed on the user's system. Stick to POSIX regex features if...
=. When it is used, the string to the right of the operator is considered an extended regular expression and matched accordingly (as in regex(3)). The return value is 0 if the string matches the pattern, and 1 otherwise. If the regular expression is syntactically incorrect, the ...
Comparison operators are used in bash to compare two strings to check if they are equal or not. Here, we will list some comparison operators including, string, and integer operators. Integer Operators Regular Expressions Regular expressions are shortened as ‘regexp' or ‘regex'. They are string...
Use regex on a stringThe result of bash's regex matching can be used to replace sed for a large number of use-cases.CAVEAT: This is one of the few platform dependent bash features. bash will use whatever regex engine is installed on the user's system. Stick to POSIX regex features if...