问题描述
我要运行此cmd行脚本
$ script.sh lib/* ../test_git_thing
我希望它处理/lib文件夹中的所有文件.
FILES = $ 1对于$ FILES中的f做回声正在处理$ f文件..."完毕
当前它仅打印第一个文件.如果我使用$ @,它会给我所有文件,但会提供我不需要的最后一个参数.有什么想法吗?
在bash和ksh中,您可以迭代除最后一个参数以外的所有参数,例如:
for"$ {@:1:$#-1}"中的f;做回声"$ f"完毕
在zsh中,您可以执行类似的操作:
for $ @ [1,$ {#}-1]中的f;做回声"$ f"完毕
$#
是参数的数量, $ {@:start:length}
是bash和ksh中的子字符串/子序列符号,而 $ @ [start,end]
是zsh中的子序列.在所有情况下,下标表达式都被视为算术表达式,这就是 $#-1
起作用的原因.(在zsh中,您需要 $ {#}-1
,因为 $#-
被解释为" $-
的长度".)/p>
在所有三个shell中,您可以将 $ {x:start:length}
语法与标量变量一起使用,以提取子字符串.在bash和ksh中,可以将 $ {a [@]:start:length}
与数组一起使用以提取值的子序列.
I want to run this cmd line script
$ script.sh lib/* ../test_git_thing
I want it to process all the files in the /lib folder.
FILES=$1
for f in $FILES
do
echo "Processing $f file..."
done
Currently it only prints the first file. If I use $@, it gives me all the files, but also the last param which I don't want. Any thoughts?
In bash and ksh you can iterate through all arguments except the last like this:
for f in "${@:1:$#-1}"; do
echo "$f"
done
In zsh, you can do something similar:
for f in $@[1,${#}-1]; do
echo "$f"
done
$#
is the number of arguments and ${@:start:length}
is substring/subsequence notation in bash and ksh, while $@[start,end]
is subsequence in zsh. In all cases, the subscript expressions are evaluated as arithmetic expressions, which is why $#-1
works. (In zsh, you need ${#}-1
because $#-
is interpreted as "the length of $-
".)
In all three shells, you can use the ${x:start:length}
syntax with a scalar variable, to extract a substring; in bash and ksh, you can use ${a[@]:start:length}
with an array to extract a subsequence of values.
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