如何在 Bash 中连接文件中的所有行？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/8013140/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to concatenate all lines from a file in Bash?
提问by Yugal Jindle
I have a file csv:
我有一个文件csv：
data1,data2,data2
data3,data4,data5
data6,data7,data8
I want to convert it to (Contained in a variable):
我想将其转换为（包含在变量中）：
variable=data1,data2,data2%0D%0Adata3,data4,data5%0D%0Adata6,data7,data8
variable=data1,data2,data2%0D%0Adata3,data4,data5%0D%0Adata6,data7,data8
My attempt :
我的尝试：
data=''
cat csv | while read line
do
data="${data}%0D%0A${line}"
done
echo $data # Fails, since data remains empty (loop emulates a sub-shell and looses data)
Please help..
请帮忙..
回答by Marc B
Simpler to just strip newlines from the file:
从文件中删除换行符更简单：
tr '\n' '' < yourfile.txt > concatfile.txt
回答by Andrew Schulman
In bash,
在 bash 中，
data=$(
while read line
do
echo -n "%0D%0A${line}"
done < csv)
In non-bash shells, you can use `...`instead of $(...). Also, echo -n, which suppresses the newline, is unfortunately not completely portable, but again this will work in bash.
在非 bash shell 中，您可以使用`...`代替$(...). 此外，echo -n，抑制换行符，不幸的是不是完全可移植的，但这同样适用于 bash。
回答by sorpigal
Some of these answers are incredibly complicated. How about this.
其中一些答案非常复杂。这个怎么样。
data="$(xargs printf ',%s' < csv | cut -b 2-)"
or
或者
data="$(tr '\n' ',' < csv | cut -b 2-)"
Too "external utility" for you?
对你来说太“外部效用”了吗？
IFS=$'\n', read -d'data="$(tr ' ' , <<<"${data[@]}")"
' -a data < csv
Now you have an array! Output it however you like, perhaps with
现在你有了一个数组！随心所欲地输出它，也许用
data="$(printf "${data[0]}" ; printf ',%s' "${data[@]:1:${#data}}")"
Still too "external utility?" Well fine,
还是太“外在效用”？好吧，
data="$(echo -n "${data[0]}" ; for d in "${data[@]:1:${#data[@]}}" ; do echo -n ,"$d" ; done)"
Yes, printfcan be a builtin. If it isn't but your echois and it supports -n, use echo -ninstead:
是的，printf可以是内置的。如果不是，但您echo是并且它支持-n，请echo -n改用：
for line in $(cat file.txt); do echo -n $line; done
Okay, now I admit that I am getting a bit silly. Andrew's answer is perfectly correct.
好吧，现在我承认我有点傻了。安德鲁的回答是完全正确的。
回答by Alexandre Mélard
I would much prefer a loop:
我更喜欢循环：
variable=$(
RS=""
while read line; do
printf "%s%s" "$RS" "$line"
RS='%0D%0A'
done < filename
)
Note: This solution requires the input file to have a new line at the end of the file or it will drop the last line.
注意：此解决方案要求输入文件在文件末尾有一个新行，否则会删除最后一行。
回答by glenn Hymanman
Another short bash solution
另一个简短的 bash 解决方案
awk 'END { print r }
{ r = r ? r OFS data=
while IFS= read -r; do
[ -n "$data" ] &&
data=$data%0D%0A$REPLY ||
data=$REPLY
done < infile
printf '%s\n' "$data"
: data=
while IFS= read -r; do
[[ -n $data ]] &&
data+=%0D%0A$REPLY ||
data=$REPLY
done < infile
printf '%s\n' "$data"
}
' OFS='%0D%0A' infile
回答by Dimitre Radoulov
while read line; do
# ...
done < csv
With shell:
随着壳：
output=$(echo $(cat ./myFile.txt) | sed 's/ /%0D%0A/g')
Recent bashversions:
最近的bash版本：
##代码##回答by themel
Useless use of cat, punished! You want to feed the CSV into the loop
用猫没用，受罚！您想将 CSV 输入循环
##代码##回答by BiS
A very simple single-line solution which requires no extra files as its quite easy to understand (I think, just cat the file together and perform sed-replace):
一个非常简单的单行解决方案，不需要额外的文件，因为它很容易理解（我认为，只需将文件放在一起并执行 sed-replace）：
##代码##