Lets say my data looks like this
iqwertyuiop
and I want to replace all the letters i after column 3 with a Z.. so my output would look like this
iqwertyuZop
How can I do this with sed or awk?
It's not clear what you mean by "column" but maybe this is what you want using GNU awk for gensub():
$ echo iqwertyuiop | awk '{print substr($0,1,3) gensub(/i/,"Z","g",substr($0,4))}'
iqwertyuZop
Perl is handy for this: you can assign to a substring
$ echo "iiiiii" | perl -pe 'substr($_,3) =~ s/i/Z/g'
iiiZZZ
This would totally be ideal for the tr command, if only you didn't have the requirement that the first 3 characters remain untouched.
However, if you are okay using some bash tricks plus cut and paste, you can split the file into two parts and paste them back together afterwords:
paste -d'\0' <(cut -c-3 foo) <(cut -c4- foo | tr i Z)
The above uses paste to rejoin together the two parts of the file that get split with cut. The second section is piped through tr to translate i's to Z's.
(1) Here's a short-and-simple way to accomplish the task using GNU sed:
sed -r -e ':a;s/^(...)([^i]*)i/\1\2Z/g;ta'
This entails looping (t), and so would not be as efficient as non-looping approaches. The above can also be written using escaped parentheses instead of unescaped characters, and so there is no real need for the -r option. Other implementations of sed should (in principle) be up to the task as well, but your MMV.
(2) It's easy enough to use "old awk" as well:
awk '{s=substr($0,4);gsub(/i/,"Z",s); print substr($0,1,3) s}'
The most intuitive way would be to use awk:
awk 'BEGIN{FS="";OFS=FS}{for(i=4;i<=NF;i++){if($i=="i"){$i="Z"}}}1' file
FS="" splits the input string by characters into fields. We iterate trough character/field 4 to end and replace i by Z.
The final 1 evaluates to true and make awk print the modified input line.
With sed it looks not very intutive but still it is possible:
sed -r '
h # Backup the current line in hold buffer
s/.{3}// # Remove the first three characters
s/i/Z/g # Replace all i by Z
G # Append the contents of the hold buffer to the pattern buffer (this adds a newline between them)
s/(.*)\n(.{3}).*/\2\1/ # Remove that newline ^^^ and assemble the result
' file
Related
I have got the following URL:
https://xcg5847#git.rz.bankenit.de/scm/smat/sma-mes-test.git
I need to pull out smat-mes-test and smat:
git config --local remote.origin.url|sed -n 's#.*/\([^.]*\)\.git#\1#p'
sma-mes-test
This works. But I also need the project name, which is smat
I am not really familiar to complex regex and sed, I was able to find the other command in another post here. Does anyone know how I am able to extract the smat value here?
With your shown samples please try following awk code. Simple explanation would be, setting field separator(s) as / and .git for all the lines and in main program printing 3rd last and 3nd last elements from the line.
your_git_command | awk -F'/|\\.git' '{print $(NF-2),$(NF-1)}'
Your sed is pretty close. You can just extend it to capture 2 values and print them:
git config --local remote.origin.url |
sed -E 's~.*/([^/]+)/([^.]+)\.git$~\1 \2~'
smat sma-mes-test
If you want to populate shell variable using these 2 values then use this read command in bash:
read v1 v2 < <(git config --local remote.origin.url |
sed -E 's~.*/([^/]+)/([^.]+)\.git$~\1 \2~')
# check variable values
declare -p v1 v2
declare -- v1="smat"
declare -- v2="sma-mes-test"
Using sed
$ sed -E 's#.*/([^/]*)/#\1 #' input_file
smat sma-mes-test.git
I would harness GNU AWK for this task following way, let file.txt content be
https://xcg5847#git.rz.bankenit.de/scm/smat/sma-mes-test.git
then
awk 'BEGIN{FS="/"}{sub(/\.git$/,"",$NF);print $(NF-1),$NF}' file.txt
gives output
smat sma-mes-test
Explanation: I instruct GNU AWK that field separator is slash character, then I replace .git (observe that . is escaped to mean literal dot) adjacent to end ($) in last field ($NF), then I print 2nd from end field ($(NF-1)) and last field ($NF), which are sheared by space, which is default output field separator, if you wish to use other character for that purpose set OFS (output field separator) in BEGIN. If you want to know more about NF then read 8 Powerful Awk Built-in Variables – FS, OFS, RS, ORS, NR, NF, FILENAME, FNR
(tested in gawk 4.2.1)
Why not sed 's!.*/\(.*/.*\)!\1!'?
string=$(config --local remote.origin.url | tail -c -21)
var1=$(echo "${string}" | cut -d'/' -f1)
var2=$(echo "${string}" | cut -d'/' -f2 | sed s'#\.git##')
If you have multiple urls with variable lengths, this will not work, but if you only have the one, it will.
var1=smat
var2=sma-mes-test.git
If I did have something variable, personally I would replace all of the forward slashes with carriage returns, throw them into a file, and then export the last and second last lines with ed, which would give me the two last segments of the url.
Regular expressions literally give me a migraine headache, but as long as I can get everything on its' own line, I can quite easily bypass the need for them entirely.
I read from stdin lines which contain fields. The field delimiter is a semicolon. There are no specific quoting characters in the input (i.e. the fields can't contain themselves semicolons or newline characters). The number of the input fields is unknown, but it is at least 4.
The output is supposed to be a similar file, consisting of the fields from 2 to the end, but field 2 and 3 reversed in order.
I'm using zsh.
I came up with a solution, but find it clumsy. In particular, I could not think of anything specific to zsh which would help me here, so basically I reverted to awk. This is my approach:
awk -F ';' '{printf("%s", $3 ";" $2); for(i=4;i<=NF;i++) printf(";%s", $i); print "" }' <input_file >output_file
The first printf takes care about the two reversed fields, and then I use an explicit loop to write out the remaining fields. Is there a possibility in awk (or gawk) to print a range of fields in a single command? Or did I miss some incredibly clever feature in zsh, which could make my life simpler?
UPDATE: Example input data
a;bb;c;D;e;fff
gg;h;ii;jj;kk;l;m;n
Should produce the output
c;bb;D;e;fff
ii;h;jj;kk;l;m;n
Using any awk in any shell on every Unix box:
$ awk 'BEGIN{FS=OFS=";"} {t=$3; $3=$2; $2=t; sub(/[^;]*;/,"")} 1' file
c;bb;D;e;fff
ii;h;jj;kk;l;m;n
With GNU awk you could try following code. Using match function ogf GNU awk, where using regex ^[^;]*;([^;]*;)([^;]*;)(.*)$ to catch the values as per requirement, this is creating 3 capturing groups; whose values are getting stored into array named arr(GNU awk's functionality) and then later in program printing values as per requirement.
Here is the Online demo for used regex.
awk 'match($0,/^[^;]*;([^;]*;)([^;]*;)(.*)$/,arr){
print arr[2] arr[1] arr[3]
}
' Input_file
If perl is accepted, it provides a join() function to join elements on a delimiter. In awk though you'd have to explicitly define one (which isn't complex, just more lines of code)
perl -F';' -nlae '$t = #F[2]; #F[2] = #F[1]; $F[1] = $t; print join(";", #F[1..$#F])' file
With sed, perl, hck and rcut (my own script):
$ sed -E 's/^[^;]+;([^;]+);([^;]+)/\2;\1/' ip.txt
c;bb;D;e;fff
ii;h;jj;kk;l;m;n
# can also use: perl -F';' -lape '$_ = join ";", #F[2,1,3..$#F]' ip.txt
$ perl -F';' -lane 'print join ";", #F[2,1,3..$#F]' ip.txt
c;bb;D;e;fff
ii;h;jj;kk;l;m;n
# -d and -D specifies input/output separators
$ hck -d';' -D';' -f3,2,4- ip.txt
c;bb;D;e;fff
ii;h;jj;kk;l;m;n
# syntax similar to cut, but output field order can be different
$ rcut -d';' -f3,2,4- ip.txt
c;bb;D;e;fff
ii;h;jj;kk;l;m;n
Note that the sed version will preserve input lines with less than 3 fields.
$ cat ip.txt
1;2;3
apple;fig
abc
$ sed -E 's/^[^;]+;([^;]+);([^;]+)/\2;\1/' ip.txt
3;2
apple;fig
abc
$ perl -F';' -lane 'print join ";", #F[2,1,3..$#F]' ip.txt
3;2
;fig
;
Another awk variant:
awk 'BEGIN{FS=OFS=";"} {$1=$3; $3=""; sub(/;;/, ";")} 1' file
c;bb;D;e;fff
ii;h;jj;kk;l;m;n
With gnu awk and gensub switching the position of 2 capture groups:
awk '{print gensub(/^[^;]*;([^;]*);([^;]*)/, "\\2;\\1", 1)}' file
The pattern matches
^ Start of string
[^;]*; Negated character class, match optional chars other than ; and then match ;
([^;]*);([^;]*) 2 capture groups, both capturing chars other than ; and match ; in between
Output
c;bb;D;e;fff
ii;h;jj;kk;l;m;n
awk '{print $3, $0}' {,O}FS=\; < file | cut -d\; -f1,3,5-
This uses awk to prepend the third column, then pipes to cut to extract the desired columns.
Here is one way to do it using only zsh:
rearrange() {
local -a lines=(${(#f)$(</dev/stdin)})
for line in $lines; do
local -a flds=(${(s.;.)line})
print $flds[3]';'$flds[2]';'${(j.;.)flds[4,-1]}
done
}
The same idea in a single line. This may not be an improvement over your awk script:
for l in ${(#f)$(<&0)}; print ${${(A)i::=${(s.;.)l}}[3]}\;$i[2]\;${(j.;.)i:3}
Some of the pieces:
$(</dev/stdin) - read from stdin using pseudo-device.
$(<&0) - another way to read from stdin.
(f) - parameter expansion flag to split by newlines.
(#) - treat split as an array.
(s.;.) - split by semicolon.
$flds[3] - expands to the third array element.
$flds[4,-1] - fourth, fifth, etc. array elements.
$i:3 - ksh-style array slice for fourth, fifth ... elements.
Mixing styles like this can be confusing, even if it is slightly shorter.
(j.;.) - join array by semicolon.
i::= - assign the result of the expansion to the variable i.
This lets us use the semicolon-split fields later.
(A)i::= - the (A) flag ensures i is an array.
In the following file I want to replace all the ; by , with the exception that, when there is a string (delimited with two "), it should not replace the ; inside it.
Example:
Input
A;B;C;D
5cc0714b9b69581f14f6427f;5cc0714b9b69581f14f6428e;1;"5cc0714b9b69581f14f6427f;16a4fba8d13";xpto;
5cc0723b9b69581f14f64285;5cc0723b9b69581f14f64294;2;"5cc0723b9b69581f14f64285;16a4fbe3855";xpto;
5cc072579b69581f14f6428a;5cc072579b69581f14f64299;3;"5cc072579b69581f14f6428a;16a4fbea632";xpto;
output
A,B,C,D
5cc0714b9b69581f14f6427f,5cc0714b9b69581f14f6428e,1,"5cc0714b9b69581f14f6427f;16a4fba8d13",xpto,
5cc0723b9b69581f14f64285,5cc0723b9b69581f14f64294,2,"5cc0723b9b69581f14f64285;16a4fbe3855",xpto,
5cc072579b69581f14f6428a,5cc072579b69581f14f64299,3,"5cc072579b69581f14f6428a;16a4fbea632",xpto,
For sed I have: sed 's/;/,/g' input.txt > output.txt but this would replace everything.
The regex for the " delimited string: \".*;.*\" .
(A regex for hexadecimal would be better -- something like: [0-9a-fA-F]+)
My problem is combining it all to make a grep -o / sed that replaces everything except for that pattern.
The file size is in the order of two digit Gb (max 99Gb), so performance is important. Relevant.
Any ideas are appreciated.
sed is for doing simple s/old/new on individual strings. grep is for doing g/re/p. You're not trying to do either of those tasks so you shouldn't be considering either of those tools. That leaves the other standard UNIX tool for manipulating text - awk.
You have a ;-separated CSV that you want to make ,-separated. That's simply:
$ awk -v FPAT='[^;]*|"[^"]+"' -v OFS=',' '{$1=$1}1' file
A,B,C,D
5cc0714b9b69581f14f6427f,5cc0714b9b69581f14f6428e,1,"5cc0714b9b69581f14f6427f;16a4fba8d13",xpto,
5cc0723b9b69581f14f64285,5cc0723b9b69581f14f64294,2,"5cc0723b9b69581f14f64285;16a4fbe3855",xpto,
5cc072579b69581f14f6428a,5cc072579b69581f14f64299,3,"5cc072579b69581f14f6428a;16a4fbea632",xpto,
The above uses GNU awk for FPAT. See What's the most robust way to efficiently parse CSV using awk? for more details on parsing CSVs with awk.
If I get correctly your requirements, one option would be to make a three pass thing.
From your comment about hex, I'll consider nothing like # will come in the input so you can do (using GNU sed) :
sed -E 's/("[^"]+);([^"]+")/\1#\2/g' original > transformed
sed -i 's/;/,/g' transformed
sed -i 's/#/;/g' transformed
The idea being to replace the ; when within quotes by something else and write it to a new file, then replace all ; by , and then set back the ; in place within the same file (-i flag of sed).
The three pass can be combined in a single command with
sed -E 's/("[^"]+);([^"]+")/\1#\2/g;s/;/,/g;s/#/;/g' original > transformed
That said, there's probably a bunch of csv parser witch already handle quoted fields that you can probably use in the final use case as I bet this is just an intermediary step for something else later in the chain.
From Ed Morton's comment: if you do it in one pass, you can use \n as replacement separator as there can't be a newline in the text considered line by line.
This might work for you (GNU sed):
sed -E ':a;s/^([^"]*("[^"]*"[^"]*)*"[^";]*);/\1\n/;ta;y/;/,/;y/\n/;/' file
Replace ;'s inside double quotes with newlines, transpose ;'s to ,'s and then transpose newlines to ;'s.
I have a file containing some data and I want to use only the first column as a stdin for my script, but I'm having trouble extracting it.
I tried using this
awk -F"\t" '{print $1}' inputs.tsv
but it only shows the first letter of the first column. I tried some other things but it either shows the entire file or just the first letter of the first column.
My file looks something like this:
Harry_Potter 1
Lord_of_the_rings 10
Shameless 23
....
You can use cut which is available on all Unix and Linux systems:
cut -f1 inputs.tsv
You don't need to specify the -d option because tab is the default delimiter. From man cut:
-d delim
Use delim as the field delimiter character instead of the tab character.
As Benjamin has rightly stated, your awk command is indeed correct. Shell passes literal \t as the argument and awk does interpret it as a tab, while other commands like cut may not.
Not sure why you are getting just the first character as the output.
You may want to take a look at this post:
Difference between single and double quotes in Bash
Try this (better rely on a real csv parser...):
csvcut -c 1 -f $'\t' file
Check csvkit
Output :
Harry_Potter
Lord_of_the_rings
Shameless
Note :
As #RomanPerekhrest said, you should fix your broken sample input (we saw spaces where tabs are expected...)
I have file with Nth columns
I want to remove the 5th column from last of Nth columns
Delimiter is "|"
I tested with simple example as shown below:
bash-3.2$ echo "1|2|3|4|5|6|7|8" | nawk -F\| '{print $(NF-4)}'
4
Expecting result:
1|2|3|5|6|7|8
How should I change my command to get the desired output?
If I understand you correctly, you want to use something like this:
sed -E 's/\|[^|]*((\|[^|]*){4})$/\1/'
This matches a pipe character \| followed by any number of non-pipe characters [^|]*, then captures 4 more of the same pattern ((\|[^|]*){4}). The $ at the end matches the end of the line. The first part of the match (i.e. the fifth field from the end) is dropped.
Testing it out:
$ sed -E 's/\|[^|]*((\|[^|]*){4})$/\1/' <<<"1|2|3|4|5|6|7"
1|2|4|5|6|7
You could achieve the same thing using GNU awk with gensub but I think that sed is the right tool for the job in this case.
If your version of sed doesn't support extended regex syntax with -E, you can modify it slightly:
sed 's/|[^|]*\(\(|[^|]*\)\{4\}\)$/\1/'
In basic mode, pipes are interpreted literally but parentheses for capture groups and curly brcneed to be escaped.
AWK is your friend :
Sample Input
A|B|C|D|E|F|G|H|I
A|B|C|D|E|F|G|H|I|A
A|B|C|D|E|F|G|H|I|F|E|D|O|R|Q|U|I
A|B|C|D|E|F|G|H|I|E|O|Q
A|B|C|D|E|F|G|H|I|X
A|B|C|D|E|F|G|H|I|J|K|L
Script
awk 'BEGIN{FS="|";OFS="|"}
{$(NF-5)="";sub(/\|\|/,"|");print}' file
Sample Output
A|B|C|E|F|G|H|I
A|B|C|D|F|G|H|I|A
A|B|C|D|E|F|G|H|I|F|E|O|R|Q|U|I
A|B|C|D|E|F|H|I|E|O|Q
A|B|C|D|F|G|H|I|X
A|B|C|D|E|F|H|I|J|K|L
What we did here
As you are aware awk's has special variables to store each field in the record, which ranges from $1,$2 upto $(NF)
To exclude the 5th from the last column is as simple as
Emptying the colume ie $(NF-5)=""
Removing from the record, the consecutive | formed by the above step ie do sub(/\|\|/,"|")
another alternative, using #sjsam's input file
$ rev file | cut -d'|' --complement -f6 | rev
A|B|C|E|F|G|H|I
A|B|C|D|F|G|H|I|A
A|B|C|D|E|F|G|H|I|F|E|O|R|Q|U|I
A|B|C|D|E|F|H|I|E|O|Q
A|B|C|D|F|G|H|I|X
A|B|C|D|E|F|H|I|J|K|L
not sure you want the 5'th from the last or 6th. But it's easy to adjust.
Thanks for the help and guidance.
Below is what I tested:
bash-3.2$ echo "1|2|3|4|5|6|7|8|9" | nawk 'BEGIN{FS="|";OFS="|"} {$(NF-4)="!";print}' | sed 's/|!//'
Output: 1|2|3|4|6|7|8|9
Further tested on the file that I have extracted from system and so it worked fine.