Question

我想通过辩论显示向我手稿提供的文件内容。我需要利用正常的((a) lo和NOT(x) a。

This is my code. How should i put the file name correctly for that cat command?

for (( i=1;$i<=$#;i=$i+2 ))
do
    cat  $ $i   #display the contents of the file currently being traversed
done

Answer 1

你们可以使用这样的东西:

for (( i=1;$i<=$#;i=$i+1 ))
do
    cat ${!i}  #display the contents of the file currently being traversed
done

相应的手册部分:

If the first character of parameter is an exclamation point, a level of variable indirection is introduced. Bash uses the value of the variable formed from the rest of parameter as the name of the variable; this variable is then expanded and that value is used in the rest of the substitution, rather than the value of parameter itself. This is known as indirect expansion. The exceptions to this are the expansions of ${!prefix*} and ${!name[@]} described below. The exclamation point must immediately follow the left brace in order to introduce indirection.

Answer 2

诉讼的正常行为是回避论点。 3. 对所有论点进行回顾:

#!/bin/sh -e
for x; do cat $x; done

你可以稍作修改,只能根据你在很多不同场合所做的一切其他论点来做。一种可能性是:

for x; do expr $(( i++ )) % 2 > /dev/null || cat "$x"; done

如果你坚持使用非标准表格,你可以使用“i!var} bashism”,而后者在绝大多数炮弹中将失败,或者你可以使用<代码>eval<>。

for (( i = 1; i <= $#; i += 2 ))
do
    eval cat  "$ $i"
done

友情链接