some_variable="rs-123.host.com";# declare and define variablecase$some_variableinab*.host.com)echo"First 2 characters were ab";;# the command below stays the same 上面的命令与我们上面使用的更复杂的 case 结构相同。 在If-Else 结构中使用正则表达式进行字符串匹配 编写强大的字符串匹配算法的另一...
Thepatternwillmatchif itmatchesanypartofthe string. Anchor thepatternusingthe ‘^’and‘$’ regular expression operatorstoforce ittomatchthe entire string. Thearrayvariable BASH_REMATCH records which partsofthe string matched the pattern. The elementofBASH_REMATCHwithindex0containstheportionofthe string...
The pattern will match if it matches any part of the string. Anchor the pattern using the ‘^’ and ‘$’ regular expression operators to force it to match the entire string. The array variable BASH_REMATCH records which parts of the string matched the pattern. The element of BASH_REMATC...
$ ls -l | > while read perms links owner group size month day time file > do > printf "%10d %s\n" "$size" "$file" > totalsize=$(( ${totalsize:=0} + ${size:-0} )) > done $ echo ${totalsize-unset} ## print "unset" if variable is not set unset 通过使用进程替换,变量t...
boolean matches(String regex) 通知此字符串是否匹配给定的正则表达式。 String str = "123456"; String re = "\\d+"; if (str.matches(re)) { // do something } Pattern类和Matcher类 String str = "abc efg ABC"; String re = "a|f"; //表示a或f ...
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sexit status. The exit status of a program is an integer which indicates whether the program was executed successfully or if an error occurred. The exit status of the last program run is stored in the question mark variable ($?). We can take a look at the exit status of the last ...
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...
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. ? The preceding item is optional and will be matched, at...
String.matches方法 booleanmatches(Stringregex) 通知此字符串是否匹配给定的正则表达式。 Stringstr="123456"; Stringre="\\d+"; if(str.matches(re)){ //dosomething } Pattern类和Matcher类 Stringstr="abcefgABC"; Stringre="a|f";//表示a或f Patternp=Patternpile(re); Matcherm=p.matcher(str); ...