Common operations of variable quantum strings in shell scripts

String manipulation

${#string} The number of characters in the output sentence

${string:position:length} output $position The length of the start of the character

${string:position}

[[email protected] scripts]# liuyifei=] i like sanpan i like luo  Swimming "[[email protected] scripts]# echo ${#liuyifei}33[[email protected]  Scripts]# echo ${liuyifei:2:4}like[[email protected] scripts]# echo ${liuyifei:2 }  like sanpan i like luo swimming==== above measured      ${ String#substring} is retrieved from the front of the string, as long as the match to the character begins to delete the shortest match      ${string# #substring} from the beginning to the longest delete      ${string%substring} starts at the end of      ${string%%substring} from the end, Similar to above ##====== must be matched from the beginning on [[Email protected] scripts]# echo ${liuyifei#like}i like  sanpan i like luo swimming[[email protected] scripts]# echo ${ Liuyifei#*like}sanpan i like luo swimming[[email protected] scripts]# echo  ${liuyifei##*like}luo swimming[[email protected] scripts]# echo ${liuyifei%*like} i like  sanpan i like luo swimming[[email protected] scripts]# echo ${ Liuyifei%like} i like sanpan i like luo swimming[[email protected]  scripts]# echo ${liuyifei%like*}i like sanpan i[[email protected]  Scripts]# echo ${liuyifei%%like*}i

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${string/substring/replace} replaces the first encountered match character

${string/#substring/replace} prefix match, must match all, replace a strip

${string/%substring/replace} forward, replace the last encountered match character, must match all

[[email protected] scripts]# echo ${liuyifei/like/love}

I love Sanpan i like Luo swimming

[[email protected] scripts]# echo ${liuyifei/#*like/love}

Love Luo swimming

[[email protected] scripts]# echo ${liuyifei/%like*/love}

I love

Personal Summary: #% appears in the shell variable operation must always be matched for related operations

Common operations of variable quantum strings in shell scripts