在 bash 中，“for;do echo;done”在空格处分割线
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in bash, "for;do echo;done" splits lines at spaces
提问by atheaos
In bash on Mac OSX, I have a file (test case) that contains the lines
在 Mac OSX 上的 bash 中，我有一个包含以下行的文件（测试用例）
x xx xxx
xxx xx x
But when I execute the command
但是当我执行命令时
for i in `cat r.txt`; do echo "$i"; done
the result is not
结果不是
x xx xxx
xxx xx x
as I want but rather
如我所愿，而是
x
xx
xxx
xxx
xx
x
How do I make echo give me 'x xx xxx'?
我如何让 echo 给我 'x xx xxx'？
回答by Oliver Charlesworth
By default, a Bash for loop splits on all whitespace. You can override that by setting the IFSvariable:
默认情况下，Bash for 循环在所有空白处拆分。您可以通过设置IFS变量来覆盖它：
IFS=$'\n'
for i in `cat r.txt`; do echo "$i"; done
unset IFS
回答by fge
Either setting IFSas suggested or use while:
IFS按照建议设置或使用while：
while read theline; do echo "$theline"; done <thefile
回答by Arenielle
IFS="\n"
for i in `cat r.txt`; do echo "$i"; done
unset IFS
