Checks if String contains a search String, handling null. This method uses String.indexOf(String). A null String will return false. StringUtils.contains(null, *) = false StringUtils.contains(*, null) = false StringUtils.contains("", "") = true StringUtils.contains("abc", "") = true Str...
Check if string contains a sub-stringUsing a test:if [[ $var == *sub_string* ]]; then printf '%s\n' "sub_string is in var." fi # Inverse (substring not in string). if [[ $var != *sub_string* ]]; then printf '%s\n' "sub_string is not in var." fi # This works ...
$ ./check_substr.sh "This is a test string" "test string" "This is a test string" contains "test string" $ ./check_substr.sh "This is a test string" "is a test" "This is a test string" contains "is a test" $ ./check_substr.sh "This is a test string" "isa test" "This...
-n is one of the supported bash string comparison operators used for checking null strings in a bash script. When -n operator is used, it returns true for every case, but that’s if the string contains characters. On the other hand, if the string is empty, it won’t return true. -...
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...
Check if string contains a sub-stringUsing a test:if [[ $var == *sub_string* ]]; then printf '%s\n' "sub_string is in var." fi # Inverse (substring not in string). if [[ $var != *sub_string* ]]; then printf '%s\n' "sub_string is not in var." fi # This works ...
grep 'pattern' file: 在文件内搜索字符串比如:grep 'searchstring' file.txt cut -b colnum file: 指定欲显示的文件内容范围,并将它们输出到标准输出设备比如:输出每行第5个到第9个字符cut -b5-9 file.txt千万不要和cat命令混淆,这是两个完全不同的命令 ...
/bin/bash # declare STRING variable STRING="Hello World" #print variable on a screen echo $STRING Navigate to a directory where your hello_world.sh is located and make the file executable: $ chmod +x hello_world.sh Now you are ready to execute your first bash script:...
contains the portion of the string matching the entire regular expression. Substrings matched by parenthesized subexpressions within the regular expression are saved in the remaining BASH_REMATCH indices. The element of BASH_REMATCH with index n is the portion of the string matching the nth ...
如果if结构使用的不是test命令,而是普通命令,比如上一节的((...))算术运算,或者test命令与普通命令混用,那么可以使用 Bash 的命令控制操作符&&(AND)和||(OR),进行多个命令的逻辑运算。$ command1 && command2 $ command1 || command2对于&&操作符,先执行command1,只有command1执行成功后, 才会执行command2。