Shell string Truncation

Removes the leftmost character from the string.

[admin@v035114 ~]$ vi test.sh   1 STR="abcd"  2 STR=${STR#"a"}  3 echo $STR  4 STR=${STR%"d"}                                                                                            5 echo $STR

Execute scripts

[admin@v035114 ~]$ ./test.sh bcdbc

Symbol # indicates the leftmost side; % indicates the left and right sides. Pay attention to the reference of variables in braces. No symbol is added before. $

If the symbol string after # Or % does not match the leftmost or rightmost value

[admin@v035114 ~]$ vi test.sh   1 STR="abcd"  2 STR=${STR#"b"}  3 echo $STR  4 STR=${STR%"d"}                                                                                                             5 echo $STR

Execute scripts

[admin@v035114 ~]$ ./test.sh abcdabc

Try to intercept multiple characters. The following script will intercept the leftmost two characters AB

[admin@v035114 ~]$ vi test.sh   1 STR="abcd"  2 STR=${STR#"ab"}  3 echo $STR  4 STR=${STR%"c"}                                                                                                             5 echo $STR

Execute scripts

[admin@v035114 ~]$ ./test.sh cdcd