Read input from a csv and append that values to variable using shell script

Question

#!/bin/bash

Dir="" 
while read line
    do echo "Record is :$line"
    Dir+="Dir,$line" 
done < dir.csv 

echo $Dir

where dir.csv is an input file here which includes following data:

/example/people/
/book/
/book/english/

I would like to append the values of the rows into one variable like /example/people/,/book/,/book/english/

Is there any easy way to achieve this through shell script? above script is showing only the last value ex:/book/english/

Please, kindly edit the post enclosing and formatting your script in order to understand it better and give you a useful answer. — Antonio Petricca
– Antonio Petricca, Commented May 26, 2021 at 14:43
Keeping your current code structure, you have Dir+="Dir,$line" but you should be using Dir="$Dir,$line" or Dir="$Dir${Dir:+,}$line", where the more complex version avoids a leading comma. This works in any shell derived from the Bourne shell (sh, bash, zsh, dash, ksh, …). In Bash (and probably some other modern shells), you could use Dir+="${Dir:+,}$line", where the ${Dir:+,} part adds a comma only if Dir is set and non-empty — avoiding the leading comma again. See Shell parameter expansion. — Jonathan Leffler
– Jonathan Leffler, Commented May 26, 2021 at 15:06

xhienne · Accepted Answer · 2021-05-26 16:57:09Z

4

I don't see anything in your code that would cause your script to only show the last value.

This may be an illusion: is your dir.csv file CRLF-delimited? (DOS/Windows format) If so, remove the CR that ends each line with a utility like dos2unix or a command like tr -d '\r'.

Some notes though:

In Dir+="Dir,$line", the string Dir should probably be removed (Dir+=",$line").
You probably want to get rid off the initial comma: Dir=${Dir#,}.
All this can be simplified with the single command below:

Dir=$(paste -s -d, dir.csv)

... or, with CRLF line-endings:

Dir=$(tr -d '\r' < dir.csv | paste -s -d,)

edited May 26, 2021 at 16:57

answered May 26, 2021 at 14:56

xhienne

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Comments

Ron · Accepted Answer · 2021-05-26 15:06:31Z

1

This is easier:

xargs < dir.csv|sed 's/ /,/g'

or if you have CRLF line endings, you can clean those up with:

xargs < dir.csv|tr -d '\r'|sed 's/ /,/g'

The above proposed tr '\n' ',' < dir.csv can add an additional , at the end if the CSV ends with newline

edited May 26, 2021 at 15:06

answered May 26, 2021 at 14:55

Ron

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2 Comments

Balan Over a year ago

I would like to save all the values in the variable( ex /example/people/,/book/,/book/english/) but this also shows last row only ( ,/book/english/)

Ron Over a year ago

please check your line ending, or see my updated answer.

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