bash 将文件名变量传递给 sed 命令
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Pass filename variable into sed command
提问by Ben
I am attempting to write a small shell script that firstly defines a file name using date and then runs two sed commands which strip out certain characters.
我正在尝试编写一个小的 shell 脚本，它首先使用 date 定义一个文件名，然后运行两个 sed 命令来去除某些字符。
My code is as follows:
我的代码如下：
filename=/var/local/file1/tsv_`date '+%d%m%y'`.txt
sed -i 's/\("[^,]*\)[,]\([^"]*"\)//g' '&filename'
sed -i 's/\"//g' '&filename'
I am getting the following error:
我收到以下错误：
sed: can't read &filename: No such file or directory
sed: can't read &filename: No such file or directory
Question is, how can I pass this filename variable into the sed command?
问题是，如何将此文件名变量传递给 sed 命令？
Thanks
谢谢
回答by Eduardo Yá?ez Parareda
When doing shell scripting, for referencing variables the & (ampersand) is not used, but the $ (dollar sign):
在编写 shell 脚本时，不使用 &（与号）来引用变量，而是使用 $（美元符号）：
filename=/var/local/file1/tsv_`date '+%d%m%y'`.txt
sed -i 's/\("[^,]*\)[,]\([^"]*"\)//g' "$filename"
sed -i 's/\"//g' "$filename"
Also when referencing variables, double quotes must be used, if not, bash won't interpret the meaning of the $ sign.
同样在引用变量时，必须使用双引号，否则，bash 不会解释 $ 符号的含义。
回答by davidcondrey
You want to use double-quotes when passing a variable to sed. If you use single quotes, the variable will be read literally.
在将变量传递给sed. 如果使用单引号，变量将按字面意思读取。
To use a shell variable in a command, preface it with a dollar sign ($). This tells the command interpreter that you want the variable's value, not its name, to be used.
要在命令中使用 shell 变量，请在它前面加上美元符号 ($)。这告诉命令解释器您希望使用变量的值，而不是它的名称。
filename=/var/local/file1/tsv_`date '+%d%m%y'`.txt
sed -i 's/\("[^,]*\)[,]\([^"]*"\)//g' "$filename"
sed -i 's/\"//g' "$filename"
