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:
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..
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)
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)
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)
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)
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)
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)
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)
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 $13 value and put it in... (2 Replies)
Discussion started by: cmccabe
2 Replies
LEARN ABOUT MOJAVE
english5.18
English(3pm) Perl Programmers Reference Guide English(3pm)NAME
English - use nice English (or awk) names for ugly punctuation variables
SYNOPSIS
use English;
use English qw( -no_match_vars ) ; # Avoids regex performance penalty
# in perl 5.16 and earlier
...
if ($ERRNO =~ /denied/) { ... }
DESCRIPTION
This module provides aliases for the built-in variables whose names no one seems to like to read. Variables with side-effects which get
triggered just by accessing them (like $0) will still be affected.
For those variables that have an awk version, both long and short English alternatives are provided. For example, the $/ variable can be
referred to either $RS or $INPUT_RECORD_SEPARATOR if you are using the English module.
See perlvar for a complete list of these.
PERFORMANCE
NOTE: This was fixed in perl 5.20. Mentioning these three variables no longer makes a speed difference. This section still applies if
your code is to run on perl 5.18 or earlier.
This module can provoke sizeable inefficiencies for regular expressions, due to unfortunate implementation details. If performance matters
in your application and you don't need $PREMATCH, $MATCH, or $POSTMATCH, try doing
use English qw( -no_match_vars ) ;
. It is especially important to do this in modules to avoid penalizing all applications which use them.
perl v5.18.2 2014-01-06 English(3pm)