What is the difference in this two awk command?


 
Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers What is the difference in this two awk command?
# 1  
Old 05-26-2016
What is the difference in this two awk command?

What is the difference in these two awk command? Both returns same output but I am not sure what is the use of +0 in command 1.

Code:
awk -F "," '{print $1+0,$2+0,$3+0}'

awk -F "," '{print $1, $2, $3}'

# 2  
Old 05-26-2016
The first one turns ("casts") the "strings" into numbers.

If the output's the same on both, it's probably because the input is already numerical.

Code:
$ echo a b c | awk '{ print $1, $2, $3 }'
a b c
$ echo a b c | awk '{ print $1+0, $2, $3 }'
0 b c
$ echo a b c | awk '{ print $1+0, $2+0, $3 }'
0 0 c
$ echo a b 27 | awk '{ print $1+0, $2+0, $3 }'
0 0 27
$ echo a b 27 | awk '{ print $1+0, $2+0, $3+0 }'
0 0 27
$ echo a b 27 | awk '{ print $1+0, $2+0, $3+1 }'
0 0 28
$

This User Gave Thanks to Scott For This Post:
# 3  
Old 05-26-2016
Wonderful !!! Thanks for examples.
# 4  
Old 05-26-2016
Hello Scott/later_troy,

Adding one more small example here too. In awk, strings could be converted to numbers and numbers could be converted to strings, if the context of the awk program demands it. For example, If numeric values appear in string concatenation, they are converted to strings. Consider the following:
Code:
two = 2; three = 3
print (two three) + 4

awk 'BEGIN{two=2;three=3;print (two three)+4}'
27   ###Output

This prints the (numeric) value 27. The numeric values of the variables two and three are converted to strings and concatenated together. The resulting string is converted back to the number 23, to which 4 is then added. Also while taking 5th field of dfin BASH means to have the used file system percentage could be one more example for this too.

Thanks,
R. Singh

Last edited by RavinderSingh13; 05-26-2016 at 05:04 PM..
 
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

awk to calculate difference of split and sum the difference

In the awk I am trying to subtract the difference $3-$2 of each matching $4 before the first _ (underscore) and print that value in $13. I think the awk will do that, but added comments. What I am not sure off is how to add a line or lines that will add sum each matching $13 value and put it in... (2 Replies)
Discussion started by: cmccabe
2 Replies

2. Shell Programming and Scripting

Difference in awk output and while

so, im going over one of my scripts and trying to optimize it. i have a code like this: cksum sjreas.py | awk '{prinnt $1$2}' This does what I need. However, i dont want to call the external command awk. so im doing this: cksum sjreas.py | while OFS=' ' read v1 v2 ; do printf... (4 Replies)
Discussion started by: SkySmart
4 Replies

3. Shell Programming and Scripting

Awk: What is the difference between: X[a,b,c] - X[a][b,c] - X[a][b][c]

I have awk appearing to behave inconsistently. With the same variable it will give the message: fatal: attempt to use array `X' in a scalar context and, if I try to correct that, then: fatal: attempt to use a scalar value as array I'm using a three dimensional array. There seems to be a... (2 Replies)
Discussion started by: Fustbariclation
2 Replies

4. Shell Programming and Scripting

Simple awk command to compare two files and print first difference

Hello, I have two text files, each with a single column, file 1: 124152970 123899868 123476854 54258288 123117283 file 2: 124152970 123899868 54258288 123117283 122108330 (5 Replies)
Discussion started by: LMHmedchem
5 Replies

5. UNIX for Dummies Questions & Answers

command difference - find

Hi, What is the difference between these two? find /some_dir -type f -exec chmod 070 {} \; and chmod 070 `find /some_dir -type f` Thanks (5 Replies)
Discussion started by: lamont
5 Replies

6. Shell Programming and Scripting

AWK Script and Commandline difference

Hey there, I just stumbled upon a difference between using awk on the commandline and using it in a shellscript. I have a variable, e.g.: PROG=vim then i want to check if the package with this name is installed: TEMPVAL=$(dpkg -l | awk '{ if ($2 == "$PROG") print $2 }') (Im using... (10 Replies)
Discussion started by: MrSnail
10 Replies

7. UNIX for Dummies Questions & Answers

which command difference

What is the difference between (unix-system “which ) and which commands. For example when I use the (unix-system “which visual_elite) command I get the following result: /home/vhdl/edatools/mentor/visualelite/VisualElite-4.2.1/Linux2.4/bin/visual_elite When I do the same on... (1 Reply)
Discussion started by: mihaelab
1 Replies

8. Shell Programming and Scripting

awk command in script gives error while same awk command at prompt runs fine: Why?

Hello all, Here is what my bash script does: sums number columns, saves the tot in new column, outputs if tot >= threshold val: > cat getnon0file.sh #!/bin/bash this="getnon0file.sh" USAGE=$this" InFile="xyz.38" Min="0.05" # awk '{sum=0; for(n=2; n<=NF; n++){sum+=$n};... (4 Replies)
Discussion started by: catalys
4 Replies

9. Programming

Difference between cp and mv linux command

Hi, I am facing one problem only with mv command not with cp command. I have a test program #include <stdio.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/mount.h> #include <fcntl.h> #include <errno.h> int sync_file(char *file) { FILE *fp=NULL;... (6 Replies)
Discussion started by: dharshini123
6 Replies

10. AIX

difference between ls -b and ls command

hi anyone please tell me what is the difference between ls -b command and ls command. (1 Reply)
Discussion started by: sathish2win
1 Replies
Login or Register to Ask a Question