linux + how to delete only the matched number from line - linux

How to delete only if number is full matched
I wrote simple sed command ,the example below by sed ,
my target is to delete the number "1" from the list $NUMBERS
what I need to add to my sed syntax in order to delete only the matched number/s
my example:
[u#h w]# NUMBERS="11 12 13"
[u#h w]# DEL_NUM="1"
[u#h w]# NUMBERS="1 11 12 13"
[u#h w]# echo $NUMBERS | sed s"/$DEL_NUM/ /g"
2 3
while the expected results should be
11 12 13

echo $NUMBERS | perl -pe "s/\b$DEL_NUM\b/ /g"
\b matches word boundaries.

There is a way in sed: wrap with <> the word to be matched:
$ echo $NUMBERS | sed "s/\<$DEL_NUM\>/ /g"
11 12 13
This will only replace exact matchings.
\b reference on sidharth answer is also valid for sed:
$ echo $NUMBERS | sed "s/\b$DEL_NUM\b/ /g"
11 12 13

Using only ksh builtins:
function delnum {
typeset DEL_NUM=$1 i
shift || return
for i; do
[[ $i == $DEL_NUM ]] || print -n $i ""
done
}
DEL_NUM="1"
NUMBERS="1 11 12 13"
delnum ${DEL_NUM} ${NUMBERS}
11 12 13

Related

Put variable into sed command

I want to replace the 2 in "2p" with the i variable value each time on the for loop.
count1=0
for i in 2 3 4 5 6 7 8 9 10 11
do
var=`cat participantes | cut -d '-' -f4 | sed -n 2p`
echo $var
count1=`expr $count1 + $var`
done
echo $count1

How do I turn a text file with a single column into a matrix?

I have a text file that has a single column of numbers, like this:
1
2
3
4
5
6
I want to convert it into two columns, in the left to right order this way:
1 2
3 4
5 6
I can do it with:
awk '{print>"line-"NR%2}' file
paste line-0 line-1 >newfile
But I think the reliance on two intermediate files will make it fragile in a script.
I'd like to use something like cat file | mystery-zip-command >newfile
You can use paste to do this:
paste -d " " - - < file > newfile
You can also use pr:
pr -ats" " -2 file > newfile
-a - use round robin order
-t - suppress header and trailer
-s " " - use single space as the delimiter
-2 - two column output
See also:
Convert a text file into columns
another alternative
$ seq 6 | xargs -n2
1 2
3 4
5 6
or with awk
$ seq 6 | awk '{ORS=NR%2?FS:RS}1'
1 2
3 4
5 6
if you want the output terminate with a new line in case of odd number of input lines..
$ seq 7 | awk '{ORS=NR%2?FS:RS}1; END{ORS=NR%2?RS:FS; print ""}'
1 2
3 4
5 6
7
awk 'NR % 2 == 1 { printf("%s", $1) }
NR % 2 == 0 { printf(" %s\n", $1) }
END { if (NR % 2 == 1) print "" }' file
The odd lines are printed with no newline after them, to print the first column. The even lines are printed with a space first and a newline after, to print the second column. At the end, if there were an odd number of lines, we print a newline so we don't end in the middle of the line.
With bash:
while IFS= read -r odd; do IFS= read -r even; echo "$odd $even"; done < file
Output:
1 2
3 4
5 6
$ seq 6 | awk '{ORS=(NR%2?FS:RS); print} END{if (ORS==FS) printf RS}'
1 2
3 4
5 6
$
$ seq 7 | awk '{ORS=(NR%2?FS:RS); print} END{if (ORS==FS) printf RS}'
1 2
3 4
5 6
7
$
Note that it always adds a terminating newline - that is important as future commands might depend on it, e.g.:
$ seq 6 | awk '{ORS=(NR%2?FS:RS); print}' | wc -l
3
$ seq 7 | awk '{ORS=(NR%2?FS:RS); print}' | wc -l
3
$ seq 7 | awk '{ORS=(NR%2?FS:RS); print} END{if (ORS==FS) printf RS}' | wc -l
4
Just change the single occurrence of 2 to 3 or however many columns you want if your requirements change:
$ seq 6 | awk '{ORS=(NR%3?FS:RS); print} END{if (ORS==FS) printf RS}'
1 2 3
4 5 6
$ seq 7 | awk '{ORS=(NR%3?FS:RS); print} END{if (ORS==FS) printf RS}'
1 2 3
4 5 6
7
$ seq 8 | awk '{ORS=(NR%3?FS:RS); print} END{if (ORS==FS) printf RS}'
1 2 3
4 5 6
7 8
$ seq 9 | awk '{ORS=(NR%3?FS:RS); print} END{if (ORS==FS) printf RS}'
1 2 3
4 5 6
7 8 9
$
Short awk approach:
awk '{print ( ((getline nl) > 0)? $0" "nl : $0 )}' file
The output:
1 2
3 4
5 6
(getline nl)>0 - getline will get the next record and assign it to variable nl. The getline command returns 1 if it finds a record and 0 if it encounters the end of the file
Short GNU sed approach:
sed 'N;s/\n/ /' file
N - add a newline to the pattern space, then append the next line of input to the pattern space
s/\n/ / - replace newline with whitespace within captured pattern space
seq 6 | tr '\n' ' ' | sed -r 's/([^ ]* [^ ]* )/\1\n/g'

Sort the tab-delimited numbers on each line of a file

I'm trying to sort the numbers on each line of a file individually. The numbers within one line are separated by tabs. (I used spaces but they're actually tabs.)
For example, for the following input
5 8 7 6
1 5 6 8
8 9 7 1
the desired output would be:
5 6 7 8
1 5 6 7
1 7 8 9
My attempt so far is:
let i=1
while read line
do
echo "$line" | tr " " "\n" | sort -g
cut -f $i fileName | paste -s >> tempFile$$
((++i))
done < fileName
This is the best I got - I'm sure it can be done in 6 characters with awk/sed/perl:
while read line
do
echo $(printf "%d\n" $line | sort -n) | tr ' ' \\t >> another-file.txt
done < my-input-file.txt
Using a few features that are specific to GNU awk:
$ awk 'BEGIN{ PROCINFO["sorted_in"] = "#ind_num_asc" }
{ delete(a); n = 0; for (i=1;i<=NF;++i) a[$i];
for (i in a) printf "%s%s", i, (++n<NF?FS:RS) }' file
5 6 7 8
1 5 6 8
1 7 8 9
Each field is set as a key in the array a. In GNU awk it is possible to specify the order in which the for (i in a) loop traverses the array - here, I've set it to do so in ascending numerical order.
Here is a bash script that can do it. It takes a filename argument or reads stdin, was tested on CentOS and assumes IFS=$' \t\n'.
#!/bin/bash
if [ "$1" ] ; then exec < "$1" ; fi
cat - | while read line
do
set $line
echo $(for var in "$#"; do echo $var; done | sort -n) | tr " " "\t"
done
If you want to put the output in another file run it as:
cat input_file | sorting_script > another_file
or
sorting_script input_file > another file
Consider using perl for this:
perl -ape '#F=sort #F;$_="#F\n"' input.txt
Here -a turns on automatic field splitting (like awk does) into the array #F, -p makes it execute the script for each line and print $_ each time, and -e specifies the script directly on the command line.
Not quite 6 characters, I'm afraid, Sean.
This should have been simple in awk, but it doen't quite have the features needed. If there had been an array $# corresponding to the fields $1, $2, etc., then the solution would have been awk '{asort $#}' input.txt, but sadly no such array exits. The loops required to move the fields into an array and out of it again make it longer than the bash version:
awk '{for(i=1;i<=NF;i++)a[i]=$i;asort(a);for(i=1;i<=NF;i++)printf("%s ",a[i]);printf("\n")}' input.txt
So awk isn't the right tool for the job here. It's also a bit odd that sort itself doesn't have a switch to control its sorting direction.
Using awk
$ cat file
5 8 7 6
1 5 6 8
8 9 7 1
$ awk '{c=1;while(c!=""){c=""; for(i=1;i<NF;i++){n=i+1; if($i>$n){c=$i;$i=$n;$n=c}}}}1' file
5 6 7 8
1 5 6 8
1 7 8 9
Better Readable version
awk '{
c=1
while(c!="")
{
c=""
for(i=1;i<NF;i++)
{
n=i+1
if($i>$n)
{
c=$i
$i=$n
$n=c
}
}
}
}1
' file
If you have ksh, you may try this
#!/usr/bin/env ksh
while read line ; do
set -s +A cols $line
echo ${cols[*]}
done < "input_file"
Test
[akshay#localhost tmp]$ cat test.ksh
#!/usr/bin/env ksh
cat <<EOF | while read line ; do set -s +A cols $line; echo ${cols[*]};done
5 8 7 6
1 5 6 8
8 9 7 1
EOF
[akshay#localhost tmp]$ ksh test.ksh
5 6 7 8
1 5 6 8
1 7 8 9

How to read n-th line from a text file in bash?

Say I have a text file called "demo.txt" who looks like this:
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
Now I want to read a certain line, say line 2, with a command which will look something like this:
Line2 = read 2 "demo.txt"
So when I'll print it:
echo "$Line2"
I'll get:
5 6 7 8
I know how to use 'sed' command in order to print a n-th line from a file, but not how to read it. I also know the 'read' command but dont know how to use it in order a certain line.
Thanks in advance for the help.
Using head and tail
$ head -2 inputFile | tail -1
5 6 7 8
OR
a generalized version
$ line=2
$ head -"$line" input | tail -1
5 6 7 8
Using sed
$ sed -n '2 p' input
5 6 7 8
$ sed -n "$line p" input
5 6 7 8
What it does?
-n suppresses normal printing of pattern space.
'2 p' specifies the line number, 2 or ($line for more general), p commands to print the current patternspace
input input file
Edit
To get the output to some variable use some command substitution techniques.
$ content=`sed -n "$line p" input`
$ echo $content
5 6 7 8
OR
$ content=$(sed -n "$line p" input)
$ echo $content
5 6 7 8
To obtain the output to a bash array
$ content= ( $(sed -n "$line p" input) )
$ echo ${content[0]}
5
$ echo ${content[1]}
6
Using awk
Perhaps an awk solution might look like
$ awk -v line=$line 'NR==line' input
5 6 7 8
Thanks to Fredrik Pihl for the suggestion.
Perl has convenient support for this, too, and it's actually the most intuitive!
The flip-flop operator can be used with line numbers:
$ printf "0\n1\n2\n3\n4" | perl -ne 'printf if 2 .. 4'
1
2
3
Note that it's 1-based.
You can also mix regular expressions:
$ printf "0\n1\nfoo\n3\n4" | perl -ne 'printf if /foo/ .. -1'
foo
3
4
(-1 refers to the last line)

Sorting space delimited numbers with Linux/Bash

Is there a Linux utility or a Bash command I can use to sort a space delimited string of numbers?
Here's a simple example to get you going:
echo "81 4 6 12 3 0" | tr " " "\n" | sort -g
tr translates the spaces delimiting the numbers, into carriage returns, because sort uses carriage returns as delimiters (ie it is for sorting lines of text). The -g option tells sort to sort by "general numerical value".
man sort for further details about sort.
This is a variation from #JamesMorris answer:
echo "81 4 6 12 3 0" | xargs -n1 | sort -g | xargs
Instead of tr, I use xargs -n1 to convert to new lines. The final xargs is to convert back, to a space separated sequence of numbers.
This is a variation on ghostdog74's answer that's too big to fit in a comment. It shows digits instead of names of numbers and both the original string and the result are in space-delimited strings (instead of an array which becomes a newline-delimited string).
$ s="3 2 11 15 8"
$ sorted=$(echo $(printf "%s\n" $s | sort -n))
$ echo $sorted
2 3 8 11 15
$ echo "$sorted"
2 3 8 11 15
If you didn't use the echo when setting the value of sorted, then the string has newlines in it. In that case echoing it without quotes puts it all on one line, but, as echoing it with quotes would show, each number would appear on its own line. This is the case whether the original is an array or a string.
# demo
$ s="3 2 11 15 8"
$ sorted=$(printf "%s\n" $s | sort -n)
$ echo $sorted
2 3 8 11 15
$ echo "$sorted"
2
3
8
11
15
$ s=(one two three four)
$ sorted=$(printf "%s\n" ${s[#]}|sort)
$ echo $sorted
four one three two
Using Bash parameter expansion (to replace spaces with newlines) we can do:
str="3 2 11 15 8"
sort -n <<< "${str// /$'\n'}"
# alternative
NL=$'\n'
str="3 2 11 15 8"
sort -n <<< "${str// /${NL}}"
If you actually have a space-delimited string of numbers, then one of the other answers provided would work fine. If your list is a bash array, then:
oldIFS="$IFS"
IFS=$'\n'
array=($(sort -g <<< "${array[*]}"))
IFS="$oldIFS"
might be a better solution. The newline delimiter would help if you want to generalize to sorting an array of strings instead of numbers.
Improving on Evan Krall's nice Bash "array sort" by limiting the scope of IFS to a single command:
printf "%q\n" "${IFS}"
array=(3 2 11 15 8)
array=($(IFS=$'\n' sort -n <<< "${array[*]}"))
echo "${array[#]}"
printf "%q\n" "${IFS}"
$ awk 'BEGIN{split(ARGV[1], numbers);for(i in numbers) {print numbers[i]} }' \
"6 7 4 1 2 3" | sort -n
I added this to my .zshrc (or .bashrc) file:
#sort a space-separated list of words (e.g. a list of HTML classes)
sortwords() {
echo $1 | xargs -n1 | sort -g | xargs
}
Call it from the terminal like this:
sortwords "banana date apple cherry"
# apple banana cherry date
Thanks to #FranMowinckel and others for inspiration.

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