awk bash shell中的字符串替换

Question

cat filenames.txt
Document a.txt
Document b.txt
Document c.txt

Because I need to tar three files, so I use the command line

tar -cvzf backup.tar.gz "Document a.txt" "Document b.txt" "Document c.txt"

In order to do this:

cat filenames.txt | awk '{  how to add " "double quatation mark to file names}' | xargs tar -cvzf backup.tar.gz

Questions: 1.How to write code for awk {...}? Thanks.

2.When () is included in the filename, why tar command cannot work? How can I deal with special characters using tar?

Answer 1

You can pass a file to the tar command using -T
It will then read the file and add all files inside that.

tar -cvzf backup.tar.gz -T filenames.txt

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Example

$cat filenames.txt
Document a.txt
Document b.txt
Document c.txt

$tar -cvzf backup.tar.gz -T filenames.txt
Document a.txt
Document b.txt
Document c.txt

$tar -tvf backup.tar.gz
-rw-r--r-- me        4 2015-01-23 08:32 Document a.txt
-rw-r--r-- me        4 2015-01-23 08:32 Document b.txt
-rw-r--r-- me        4 2015-01-23 08:32 Document c.txt

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Man page entry

-T, --files-from=FILE
get names to extract or create from FILE

Answer 2

You can use xargs -I :

cat filenames.txt | xargs -I {} tar -rvf backup.tar '{}'
gzip backup.tar

Answer 3

You could also use printf , if you need to use awk and the fileformat is specified/generated like STRING<SPACE>STRING.txt .

awk '{ printf "\"%s %s\"\n", $1, $2 }' files.txt | xargs tar -cvzf backup.tgz

AWK is a great filter for processing generated rows and columns.

Since you don't need to filter the data, you could take the line as is.

$ awk '{ printf "%s\n", $0; }' files.txt | xargs -I {} tar -rvf backup.tar {}
Document A.txt
Document B.txt

Or without printf (the whole line)

$ awk '{ print; }' files.txt | xargs -I {} tar -rvf backup.tar {}

and compress it in the last step, gzip can't update compressed archives:

$ gzip backup.tar