Extracting values from specific TSV table row based on variable in bash

Question

I have a TSV table and I'm trying to use bash to extract values from a specific row based on the user's input, and then assign those values to variables for use later.

Example table (columns are tab-delimited):

NAME     FOOD     TIME
Eric     pasta    8pm
Sally    bread    11am
Jeff     ribeye steak with fries    10pm

My goal:

echo Enter your name
read name
echo Hello, $name

(Select the row that matches the $name value and assign FOOD and TIME to $food and $time respectively)

echo You'll be having $food at $time

I did some reading and perhaps awk might be able to accomplish this, but I'm completely lost. How should I go about doing this?

markp-fuso · Accepted Answer · 2020-12-02 23:09:56Z

3

Any command that can pull the 2x desired values out and display then on one line should work; from here you can read these 2x values into your variables with the read command.

Sample data:

$ cat mytsv                              # tab-delimited columns
NAME     FOOD     TIME
Eric     pasta    8pm
Sally    bread    11am
Jeff     ribeye steak with fries      10pm

We'll start by using awk to pull out the 2 fields of interest, making sure to use an output field separator that does not exist in the actual data (eg, OFS=":"):

$ name='Jeff'
$ awk -F'\t' -v ptn="${name}" 'BEGIN {OFS=":"} $1==ptn {print $2,$3}' mytsv
ribeye steak with fries:10pm

We can now combine IFS (set to :) and read to pull these values into our 2x variables, eg:

$ IFS=":" read -r food time < <(awk -F'\t' -v ptn="${name}" 'BEGIN {OFS=":"} $1==ptn {print $2,$3}' mytsv)
$ echo "${food}"
ribeye steak with fries
$ echo "${time}"
10pm
$ echo "You'll be having ${food} at ${time}"
You'll be having ribeye steak with fries at 10pm

edited Dec 2, 2020 at 23:09

answered Dec 2, 2020 at 21:45

markp-fuso

38.6k5 gold badges24 silver badges48 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

VILEWORX Over a year ago

Tried using this one but I'm getting wrong outputs (some of my tsv values have spaces in them) and I can't seem to set the separator using awk -F. How do I fix this?

markp-fuso Over a year ago

would need to see a more detailed set of input data that addresses what you're talking about; and if some of the values have white space then we'd need to see what constitutes a field separator (eg, head -4 <file> | od -c)

VILEWORX Over a year ago

For instance a fourth row in the above table that says: Jeff ribeye steak with fries 10pm My field separator is always tab.

markp-fuso Over a year ago

updated to work with the new sample data you've provided

glenn jackman Over a year ago

I'd recommend a more obvious variable name, perhaps name, instead of ptn

Raman Sailopal · Accepted Answer · 2020-12-02 21:34:03Z

3

Using GNU awk:

awk -F "\t" -v nam="$name" '$1==nam { printf "You will be having %s at %s\n",$2,$3 }' file

Set the field delimiter to tab and pass variable nam into awk using the variable name. When the first tab delimited field is equal to nam, print the 2nd and 3rd delimited fields in the format required

answered Dec 2, 2020 at 21:34

Raman Sailopal

13k2 gold badges15 silver badges21 bronze badges

1 Comment

Ed Morton Over a year ago

There's nothing GNU-specific there, it'll work in any POSIX awk.

glenn jackman · Accepted Answer · 2020-12-03 02:57:44Z

2

A bash solution:

read -p 'Enter your name: ' yourName
echo "Hello, $yourName"

found=0
while IFS=$'\t' read -r name food time; do
  if [[ "$name" == "$yourName" ]]; then
    found=1
    break
  fi
done < input.tsv

if [[ $found -eq 1 ]]; then
  echo "You'll be having $food at $time"
else
  echo "Name $yourName not found"
fi

answered Dec 3, 2020 at 2:57

glenn jackman

249k42 gold badges233 silver badges362 bronze badges

Collectives™ on Stack Overflow

Extracting values from specific TSV table row based on variable in bash

3 Answers 3

5 Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

5 Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related