36

I have a file which looks like this:

1
3
4
1
4
3
1
2

How can I find the total of this (i.e. 1+3+4+1+4+3+1+2 = 19)?

52

bc with a little help from paste to get the lines in a single one with + as the separator:

paste -sd+ file.txt | bc

To use the output of grep (or any other command) instead a static file, pass the grep's STDOUT to the STDIN of paste:

grep .... | paste -sd+ | bc

Example:

% cat file.txt            
1
3
4
1
4
3
1
2

% paste -sd+ file.txt | bc
19

% grep . file.txt | paste -sd+ | bc
19

If you must use bash, then you can use an array to save the file contents and then iterate over the elements or you can read the file line by line and do the sum for each line, the second approach would be more efficient:

$ time { nums=$(<file.txt); for i in ${nums[@]}; do (( sum+=i )); done; echo $sum ;}
19

real    0m0.002s
user    0m0.000s
sys 0m0.000s

$ time { while read i; do (( sum+=i )); done <file.txt; echo $sum ;}
19

real    0m0.000s
user    0m0.000s
sys 0m0.000s
| improve this answer | |
  • 2
    the stdin way didn't work for me until I discovered in another answer that I had to use paste -sd+ -. Please amend that. – Xerus May 4 '18 at 0:04
19

You could use awk, too. To count the total number of lines in *.txt files that contain the word "hello":

grep -ch 'hello' *.txt | awk '{n += $1}; END{print n}'

To simply sum the numbers in a file:

awk '{n += $1}; END{print n}' file.txt
| improve this answer | |
  • But if that line has the value "4" it won't count 4 will it. It will count 1. – Tim Jun 9 '16 at 20:23
  • No, it will count 4. – CrazyApe84 Jun 9 '16 at 20:23
  • I want the total of the numbers in a file. Does this do that? – Tim Jun 9 '16 at 20:24
  • I thought you changed your question to the output of grep. I was making some assumptions. I'll add how to simply sum the values in a file. – CrazyApe84 Jun 9 '16 at 20:26
  • 2
    Yeah. It's really the same answer as heemayl's, but instead of paste and bc it uses awk, which ultimately gives a lot more flexibility. Still, his answer is good and he was first so he deserves your vote! – CrazyApe84 Jun 9 '16 at 20:28
8

Use numsum from the package num-utils!

(You may need to sudo apt-get install num-utils)

The command numsum does just what you need by default;

$ numsum file.txt 
19

Reading the test numbers line by line from stdin:

$ printf '
1 
3
4
1
4
3
1
2' | numsum
19

Or reading from one line:

$ printf '1 3 4 1 4 3 1 2' | numsum -r
19

More utilities

The package contains some other utilities for number processing that deserve to be more well known:

numaverage   - find the average of the numbers, or the mode or median
numbound     - find minimum of maximum of all lines
numgrep      - to find numbers matching ranges or sets
numinterval  - roughly like the first derivative
numnormalize - normalize numbers to an interval, like 0-1
numrandom    - random numbers from ranges or sets, eg odd.  
numrange     - similar to seq
numround     - round numbers up, down or to nearest

and a more general calculator command numprocess,
that applies an expression from the command line to numbers on input lines.

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1

You can use awk, a native linux application usefull to scanning and processing files with a pattern per line. For your question, this will produce what you want:

awk 'BEGIN { sum=0 } { sum+=$1 } END {print sum }' file.txt

Pipes are also accept:

cat file.txt | awk 'BEGIN { sum=0 } { sum+=$1 } END {print sum }'
| improve this answer | |
  • There's no need for a BEGIN{} block, see CrazyApe84's answer. – terdon Jun 10 '16 at 10:39
  • It is redundant to this problem but I've preferred to include it due a didactic purpose . – gwarah Jun 10 '16 at 11:40
  • But what does it teach? It is redundant to every problem, awk is not C, you don't need to set a variable before using it. Try awk 'BEGIN{print c+=1}'. – terdon Jun 10 '16 at 11:46
  • BEGIN {} block wasn't designed just to initialize variables. It takes part on design specification. So, on some problems it could be needed. – gwarah Jun 10 '16 at 15:12
1

This is a fairly simple use of bash scripting.

SUM=0; for line in `cat file.txt`; do SUM=$((SUM + line)); done
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  • This is much simpler and toolset minimalistic than the current solution. – Det Mar 13 '19 at 12:04
  • Upvote for the simple approach, thanks! However I should mention it's not safe to use SUM as this redefines the built-in SUM in /usr/bin/SUM. – S3DEV Mar 18 at 11:25
1

Perl solution:

$ perl -lnae '$c+=$_;END{print $c}' input.txt                                                                            
19

The above can sum all numbers across multiple files:

$ perl -lnae '$c+=$_;END{print $c}' input.txt input2.txt                                                                 
34

For multiple files given on command-line where we want to see sum of numbers in individual file we can do this:

$ perl -lnae '$c+=$_;if(eof){printf("%d %s\n",$c,$ARGV);$c=0}' input.txt input2.txt                                      
19 input.txt
15 input2.txt
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1

Simple -

awk '{total+=$1} END{print total}' file

adds up the numbers and gives you the total.

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1

A simple approach is to use a built-in feature of your shell:

SUM=0; while read N; do SUM=$((SUM+N)); done </path/to/file
echo $SUM

This reads your file linewise, sums up and prints the result.

If you want to use a pipe and only use the 1st row, it works like this:

SUM=0
your_command | while read -r LINE; do for N in $LINE; do break; done; SUM=$((SUM+N)); done
echo $SUM

Getting the first element is done like this:

LIST="foo bar baz"
for OBJ in $LIST; do break; done
echo $OBJ

foo
| improve this answer | |

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