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I'm working on a bash script to backup MySQL. I need to read from a file a series of strings and pass them to a variable in my script. Example:

Something like this will be in the file (file.txt)

database1 table1
database1 table4
database2
database3 table2

My script needs to read the file and put these strings in a variable like:

#! bin/bash
LIST="database1.table1|database1.table4|database2|database3.table2"

Edit. I changed my mind, now I need this output:

database1.table1.*|database1.table4.*|database2*.*|database3.table2.*
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2
  • 2
    And what have you tried so far? Commented Apr 30, 2014 at 14:18
  • 1
    You need to fix the shebang too, it'd be #!/bin/bash Commented Apr 30, 2014 at 15:49

4 Answers 4

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6

You could use tr to replace the newlines and spaces:

LIST=$(tr ' \n' '.|' < file.txt)

Since the last line of the input file is likely to contain a newline by itself, you'd need to get rid of it:

LIST=$(tr ' ' '.' < file.txt | paste -sd'|')
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5

Using awk:

s=$(awk '{$1=$1}1' OFS='.' ORS='|' file)
LIST="${s%|}"

echo "$LIST"
database1.table1|database1.table4|database2|database3.table2
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4 Comments

This is great!!. I forgot to mention one thing. I need to also add some wildcards to the output string. The conditions are: if we read database2 the output should be database2*.* and if we read a database and a table the output should be database1.table1.* The final result I'm looking for is: database1.table1.*|database1.table4.*|database2*.*|database3.table2.* Please help :)
That actually changes the very nature of the problem. If you open a new question linking to this one I will make an attempt to solve it.
stackoverflow.com/questions/23412765/…
May I know what's wrong with the answer since you unaccepted it.
3

bash (version 4 I believe)

mapfile -t lines < file.txt           # read lines of the file into an array
lines=("${lines[@]// /.}")            # replace all spaces with dots 
str=$(IFS='|'; echo "${lines[*]}")    # join the array with pipe
echo "$str"

database1.table1|database1.table4|database2|database3.table2

mapfile -t lines < file.txt
for ((i=0; i<${#lines[@]}; i++)); do
    [[ ${lines[i]} == *" "* ]] && lines[i]+=" *" || lines[i]+="* *"
done
str=$(IFS='|'; echo "${lines[*]// /.}") 
echo "$str"

database1.table1.*|database1.table4.*|database2*.*|database3.table2.*
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2 Comments

You don't need the auxiliary variable since the purpose is only to print to stdout. In a subshell (IFS='|'; echo "${lines[*]}") is enough. Actually, you don't even need the auxiliary lines either: mapfile -t lines < files.txt; (IFS='|'; echo "${lines[*]// /.}")
How could I get this output instead database1.table1.*|database1.table4.*|database2*.*|database3.table2.* - Please notice the .* vs *.* - In other words: If there is only database with no table i need to add *.* at the end and when there is a database.table i need to add .*
2

You can just replace the new lines with a charater that you need using sed, if it doesn't occur in the data.

For example

FOO=$(sed '{:q;N;y/ /./;s/\n/|/g;t q}' /home/user/file.txt)
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1 Comment

How could I get this output instead database1.table1.*|database1.table4.*|database2*.*|database3.table2.* - Please notice the .* vs *.* - In other words: If there is only database with no table i need to add *.* at the end and when there is a database.table i need to add .*

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