在 bash 中可以用 ${parameter/pattern/string} 执行替换操作，如果 /string 是空，那么对应的就是替换为空（删除）操作。可以用于数组：
$ str="123456"
$ arr=(1 2 3 4 5 6)
$ echo ${str/1/-}
-23456
$ echo ${arr[@]/1/-}
- 2 3 4 5 6
$ echo ${arr[@]/1}
2 3 4 5 6
${parameter/pattern/string} Pattern substitution. The pattern is expanded to produce a pattern just as in pathname expansion, Parameter is expanded and the longest match of pattern against its value is replaced with string. The match is performed using the rules described under Pattern Matching below. If pattern begins with /, all matches of pattern are replaced with string. Normally only the first match is replaced. If pattern begins with #, it must match at the beginning of the expanded value of parameter. If pattern begins with %, it must match at the end of the expanded value of parameter. If string is null, matches of pattern are deleted and the / following pattern may be omitted. If the nocase- match shell option is enabled, the match is performed without regard to the case of alphabetic characters. If parameter is @ or *, the sub- stitution operation is applied to each positional parameter in turn, and the expansion is the resultant list. If parameter is an array variable subscripted with @ or *, the substitution operation is applied to each member of the array in turn, and the expansion is the resul- tant list.