How to make GREP select only numeric values? - linux

I use the df command in a bash script:
df . -B MB | tail -1 | awk {'print $4'} | grep .[0-9]*
This script returns:
99%
But I need only numbers (to make the next comparison).
If I use the grep regex without the dot:
df . -B MB | tail -1 | awk {'print $4'} | grep .[0-9]*
I receive nothing.
How to fix?

If you try:
echo "99%" |grep -o '[0-9]*'
It returns:
99
Here's the details on the -o (or --only-matching flag) works from the grep manual page.
Print only the matched (non-empty) parts of matching lines, with each such part on a separate output line. Output lines use the same delimiters as input, and delimiters are null bytes if -z (--null-data) is also used (see Other Options).

grep will print any lines matching the pattern you provide. If you only want to print the part of the line that matches the pattern, you can pass the -o option:
-o, --only-matching
Print only the matched (non-empty) parts of a matching line, with each such part on a separate output line.
Like this:
echo 'Here is a line mentioning 99% somewhere' | grep -o '[0-9]+'

How about:
df . -B MB | tail -1 | awk {'print $4'} | cut -d'%' -f1

No need to used grep here, Try this:
df . -B MB | tail -1 | awk {'print substr($5, 1, length($5)-1)'}

function getPercentUsed() {
$sys = system("df -h /dev/sda6 --output=pcent | grep -o '[0-9]*'", $val);
return $val[0];
}

Don't use more commands than necessary, leave away tail, grep and cut. You can do this with only (a simple) awk
PS: giving a block-size en print only de persentage is a bit silly ;-) So leave also away the "-B MB"
df . |awk -F'[multiple field seperators]' '$NF=="Last field must be exactly --> mounted patition" {print $(NF-number from last field)}'
in your case, use:
df . |awk -F'[ %]' '$NF=="/" {print $(NF-2)}'
output: 81
If you want to show the percent symbol, you can leave the -F'[ %]' away and your print field will move 1 field further back
df . |awk '$NF=="/" {print $(NF-1)}'
output: 81%

You can use Perl style regular expressions as well. A digit is just \d then.
grep -Po "\\d+" filename
-P Interpret PATTERNS as Perl-compatible regular expressions (PCREs).
-o Print only the matched (non-empty) parts of a matching line, with each such part on a separate output line.

Related

cut a particular number from the url in linux

I've a file with the below header generated by certain process
Link: <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=2>; rel="next", <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=8>; rel="last"
I want to cut just the number 8 from page=8 in the above content. How to go about it? Appreciate any help.
Try this -
$ cat f
Link: <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=2>; rel="next", <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=8>; rel="last"
$ awk -F'[&=<>]' '{for(i=1;i<=NF;i++) if($i ~ /^page$/) {print $(i+1)}}' f
2
8
If it is getting appended then you will get the last value using below awk :
$ awk -F'[&=<>]' '{for(i=1;i<=NF;i++) if($i ~ /^page$/) {kk=$(i+1)}} END{print kk}' ff
8
Limitation : Currently you have page=2 and page=8 and above command
will print the last page value.
And if you always want to print the 2nd value "8" (Added extra lines to the existing url, considering that it will keep on increasing and you always need the 2nd value then use below) -
$ cat f
Link: <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=2>; rel="next", <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=8>; rel="last"
<https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=8>; rel="last"
$ awk -v k=1 -F'[&=<>]' '{for(i=1;i<=NF;i++) if(($i ~ /^page$/) && (k==2) ) {print $(i+1)} k++}' f
8
Following is an implementation using grep:
grep -Po "&page=[0-9]*" <file_name> | grep -Po "[0-9]*"
Example:
echo 'Link: <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=2>; rel="next", <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=8000>; rel="last"' | grep -Po "&page=[0-9]*" | grep -Po "[0-9]*"
This will produces the result as expected.
echo 'Link: <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=2>; rel="next", <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=12345>; rel="last"' | grep -Po "&page=[0-9]*" |grep -Po "[0-9]*"| awk '2 == NR % $ct'
In awk. reverse the text, remove first [0-9]+=egap, output and rev again:
$ rev foo | awk 'sub(/[0-9]+=egap/,"")||1' |rev
Output:
Link: <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&page=2>; rel="next", <https://rnd.corp.zoom/api/v3/repositories/99/issues?state=all&per_page=100&>; rel="last"
try:
awk '{gsub(/.*page=/,"page=");sub(/>.*/,"");print}' Input_file
Simply substitute the all line with .*page= to page= which is nothing but will go till last page string(as * is a greedy regex match), so then substitute >.*(means starting from > to till end of line) with NULL, then print the line which will be page=8 or last value of the page. Off course I am considering that your Input_file is same as example shown.
awk -F'[= >]' '{print $12}' file
8
awk -F= '{split($8,a,">");print a[1]}' file
8
awk -F= '$8=="8>; rel"{print substr($8,1,1)}' file
8
The fact that a greedy regex is needed here (only the last occurrence of &page= should be matched) enables a simple sed solution:
sed -E 's/^.*&page=([0-9]+).*$/\1/' file
^.*&page= matches everything up to the last occurrence of &page on the line.
([0-9]+) matches one or more digits, and - thanks to enclosure in (...) stores the match in the 1st (and only) capture group, which the replacement string then reference as \1.
.*$ matches any remaining character on the line.
By virtue of the regex having matched the entire line, \1 therefore results in just the captured number as the output.
The above works with both GNU and BSD/macOS sed and takes advantage of modern extended regular expressions (-E), but in case you need a POSIX-compliant solution (which must use basic regular expressions and is therefore more cumbersome):
sed 's/^.*&page=\([0-9]\{1,\}\).*$/\1/' file
With GNU grep (on Linux, as requested), a single-pass grep -Po solution is also possible; like the sed solution, it relies on greedily matching up to the last &page=:
grep -Po "^.*&page=\K[0-9]+" file
-P activates support for PRCEs (Perl-compatible Regular Expressions).
-o only outputs the matching part of the line.
\K drops everything matched so far, so that what [0-9]+ matches - one or more digits - is the only output.

In bash, how to sort strings including numbers?

I have a script that outputs file paths (via find) :
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3-something16
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something1
/foo/bar/example/foo/bar/example/foo-bar-example/1.2-something5
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something2
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something10
How can I list them in Bash so that they are in ascending numeric order based on the number at the end and regardless of the version ( 1.2, 1.2.3 or 1.2.3.4)
Ps : the something part can eventually contain a dash.
Desired output :
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something1
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something2
/foo/bar/example/foo/bar/example/foo-bar-example/1.2-something5
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something10
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3-something16
I used a temporary sentinel character to delimit the number at the end but it's a little bit complicated in my case.
Extract the number at the end, prepend it to all the lines, sort numerically and finally delete that number:
sed -r 's/(.*)([^0-9])([0-9]+)$/\3\1\2\3/' file | sort -n | sed 's/^[0-9]*//'
With your input, this returns:
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something1
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something2
/foo/bar/example/foo/bar/example/foo-bar-example/1.2-something5
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something10
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3-something16
I think this is the Schwartzian transform.
By pieces:
$ sed -r 's/(.*)([^0-9])([0-9]+)$/\3\1\2\3/' a
16/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3-something16
1/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something1
5/foo/bar/example/foo/bar/example/foo-bar-example/1.2-something5
2/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something2
10/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something10
#^
#note the numbers here
$ sed -r 's/(.*)([^0-9])([0-9]+)$/\3\1\2\3/' a | sort -n
1/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something1
2/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something2
5/foo/bar/example/foo/bar/example/foo-bar-example/1.2-something5
10/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something10
16/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3-something16
# ^
# now it is ordered
$ sed -r 's/(.*)([^0-9])([0-9]+)$/\3\1\2\3/' a | sort -n | sed 's/^[0-9]*//'
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something1
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something2
/foo/bar/example/foo/bar/example/foo-bar-example/1.2-something5
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something10
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3-something16
You can use this sed + sort + awk:
sed -E 's/.*[^0-9]([0-9]+)$/\1 &/' file | sort -n | awk '{print $2}'
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something1
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something2
/foo/bar/example/foo/bar/example/foo-bar-example/1.2-something5
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3.4-something10
/foo/bar/example/foo/bar/example/foo-bar-example/1.2.3-something16
If you can ensure that you will never have a '#' character in your file, you can try:
sed -e 's/something/#/g' filename.txt | sort -t# -k2 -n | sed -e 's/#/something/g'

grep only one occurrence

I am trying to grab some content, but there are multiple instances of it in the same line. I am using this command.
grep -o -m 1 -P '(?<=sk).*(?=fa)' test.txt | head -1
However, the search ends after the second/last match. Running it on Ubuntu 14.04.2
test.txt: skjahfasdkl aklsdj laks skjahfasdkl aklsdj laks
Current Output: jahfasdkl aklsdj laks skjah
Desired output: jah
You just need non-greedy:
grep -m1 -oP '(?<=sk).*?(?=fa)' file | head -1
# ...................^^^
The -m1 will stop after the first line, but you still need head to limit to the first match.
It's greedy match, you want to treat space as delimiters so specify the match to nonspace chars, i.e.
... '(?<=sk)[^ ]*(?=fa)'
if the condition is non spaces between sk and fa ( matching in words ), you can use can use [^ ]* instead .*, as the following:
grep -o -m 1 -P '(?<=sk)[^ ]*(?=fa)' test.txt | head -1
else you can use this :
sed -e "s/sk\(.*\)fa.*$/\1/g" test.txt | sed -e "s/fa.*$//g"
test :
echo "skjahz z zfasdkl aklsdj laks skjahppppfasdkl aklsdj laks" | sed -e "s/sk\(.*\)fa.*$/\1/g" | sed -e "s/fa.*$//g"
#jahz z z
If you consider non-grep answer then this gnu-awk can do the job:
awk -v FPAT='sk[^[:blank:]]*fa' '{gsub(/^sk|fa$/, "", $1); print $1; exit}' file

Linux awk command doesn't print integers correctly?

Can someone explain why this command doesn't print out a list of PID without the newline?
I want output like:
1234 5678 123 456
I tried all these, and none of them work
ps -eww --no-headers -o pid,args | grep 'usr' | awk '{ printf "%d ", $1 }'
ps -eww --no-headers -o pid,args | grep 'usr' | awk '{ printf "%s ", $1 }'
ps -eww --no-headers -o pid,args | grep 'usr' | awk '{ print $1 }' | tr '\n' ''
ps -eww --no-headers -o pid,args | grep 'usr' | awk '{ print $1 }' | tr -d '\n'
I just found out bash works fine, but not zsh in my case
zsh has a feature of letting the user know that the last output line was partial (i.e. there were no final newline). For more details on this you can look up PROMPT_CR, PROMPT_SP and PROMPT_EOL_MARK in man zshoptions.
You can add PROMPT_EOL_MARK='' to your ~/.zshrc to make the partial line indicator empty, but I would advise against it: now we know that it's just a feature, and sometimes we can notice a problem with our data if we leave it enabled. On a reasonably powerful terminal, the percent sign (the default when PROMPT_EOL_MARK is unset) is output bold and inverted, so it can't be confused with a piece of actual output.
Your command's output is a list of pids exactly as you desired. Adding a final newline makes it also look right with zsh:
ps -eww --no-headers -o pid,args | awk '/usr/ { printf "%d ", $1 } END {print""}'
(using also another answer's idea of getting rid of grep using the power of awk).
It does for me like this:
ps -eww --no-headers -o pid,args | awk '/usr/{printf "%d ",$1}'
I.e. awk can search for strings matching regular expressions, so you don't really need grep when using awk.

Get line number while using grep

I am using grep recursive to search files for a string, and all the matched files and the lines containing that string are print on the terminal. But is it possible to get the line numbers of those lines too??
ex: presently what I get is /var/www/file.php: $options = "this.target", but what I am trying to get is /var/www/file.php: 1142 $options = "this.target";, well where 1142 would be the line number containing that string.
Syntax I am using to grep recursively is sudo grep -r 'pattern' '/var/www/file.php'
One more question is, how do we get results for not equal to a pattern. Like all the files but not the ones having a certain string?
grep -n SEARCHTERM file1 file2 ...
Line numbers are printed with grep -n:
grep -n pattern file.txt
To get only the line number (without the matching line), one may use cut:
grep -n pattern file.txt | cut -d : -f 1
Lines not containing a pattern are printed with grep -v:
grep -v pattern file.txt
If you want only the line number do this:
grep -n Pattern file.ext | gawk '{print $1}' FS=":"
Example:
$ grep -n 9780545460262 EXT20130410.txt | gawk '{print $1}' FS=":"
48793
52285
54023
grep -A20 -B20 pattern file.txt
Search pattern and show 20 lines after and before pattern
grep -nr "search string" directory
This gives you the line with the line number.
In order to display the results with the line numbers, you might try this
grep -nr "word to search for" /path/to/file/file
The result should be something like this:
linenumber: other data "word to search for" other data
When working with vim you can place
function grepn() {
grep -n $# /dev/null | awk -F $':' '{t = $1; $1 = $2; $2 = t; print; }' OFS=$':' | sed 's/^/vim +/' | sed '/:/s// /' | sed '/:/s// : /'
}
in your .bashrc and then
grepn SEARCHTERM file1 file2 ...
results in
vim +123 file1 : xxxxxxSEARCHTERMxxxxxxxxxx
vim +234 file2 : xxxxxxSEARCHTERMxxxxxxxxxx
Now, you can open vim on the correspondending line (for example line 123) by simply copying
vim +123 file1
to your shell.

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