How To Delete All Words Before X Characters - linux

I'm using code from this question How To Delete All Words After X Characters and I'm having a trouble keeping (not deleting) all the words after 30 characters.
Original code:
awk 'BEGIN{FS=OFS="" } length>30{i=30; while($i~/\w/) i++; NF=i-1; }1'
My attempt:
awk 'BEGIN{FS=OFS="" } length>30{i=30; while($i~/\w/) i++; NF=i+1; }1'
Basically, I understand I need to change the NF which was NF=i-1 so I tried changing it to NF=i+1 but obviously I'm only getting one field. How can I specify NF to print the rest of the line?
Sample data:
StackOverflow Users Are Brilliant And Hard Working
#character 30 ---------------^
Desired output:
And Hard Working
If you could please help me keep the rest of the line by using NF, I would really appreciate your positive input and support.

It is much easier using gnu grep:
grep -oP '^.{30}\w*\W*\K.*' file
And Hard Working
Where \K is used for reseting matched information.
RegEx Breakup:
^: Start
.{30}: Match first 30 characters
\w*: followed by 0 or more word characters
\W*: followed by 0 or more non-word characters
\K: reset matched information so far
.*: Match anything after this position
Using awk you can use this solution:
awk '{sub(/^.{30}[_[:alnum:]]*[[:blank:]]*/, "")} 1' file
And Hard Working
Finally a sed solution:
sed -E 's/^.{30}[_[:alnum:]]*[[:blank:]]*//' file
And Hard Working

another awk
awk '{print substr($0, index(substr($0,30),FS)+30)}'
find the delimiter index after the 30th char, take a substring from that index on.

I can't imagine why your considering anything related to NF for this since you're not doing anything with fields, you're just splitting each line at a blank char. It sounds like this is all you need for both questions, using GNU awk for gensub():
$ awk '{print gensub(/(.{30}\S*)\s+(.*)/,"\\1",1)}' file
StackOverflow Users Are Brilliant
$ awk '{print gensub(/(.{30}\S*)\s+(.*)/,"\\2",1)}' file
And Hard Working
or it's briefer using GNU sed:
$ sed -E 's/(.{30}\S*)\s+(.*)/\1/' file
StackOverflow Users Are Brilliant
$ sed -E 's/(.{30}\S*)\s+(.*)/\2/' file
And Hard Working

With the use of NF, you can try
awk '{for(i=1;i<=NF;i++){a+=length($i)+1;if(a>30){for(j=i+1;j<=NF;j++)b=b $j" ";print b;exit}}}'

cut -c30- file | cut -d' ' -f2-
this will keep only the words that start after 30th character (index >= 31)

Related

Replacing characters in each line on a file in linux

I have a file with different word in each line.
My goal is to replace the first character to a capital letter and replace the 3rd character to "#".
For example: football will be exchanged to Foo#ball.
I tried thinking about using awk and sed.It didn't help me since (to my knowledge) sed needs an exact character input and awk can print the desired character but not change it.
With GNU sed and two s commands:
echo 'football' | sed -E 's/(.)/\U\1/; s/(...)./\1#/'
Output:
Foo#ball
See: 3.3 The s Command, 5.7 Back-references and Subexpressions and 5.9.2 Upper/Lower case conversion
This might work for you (GNU sed):
sed 's/\(...\)./\u\1#/' file
With bash you can use parameter expansions alone to accomplish the task. For example, if you read each line into the variable line, you can do:
line="${line^}" # change football to Football (capitalize 1st char)
line="${line:0:3}#${line:4}" # make 4th character '#'
Example Input File
$ cat file
football
soccer
baseball
Example Use/Output
$ while read -r line; do line="${line^}"; echo "${line:0:3}#${line:4}"; done < file
Foo#ball
Soc#er
Bas#ball
While shell is typically slower, when use is limited to builtins, it doesn't fall too far behind.
(note: your question says 3rd character, but your example replaces the 4th character with '#')
With GNU awk for the 3rd arg to match():
$ echo 'football' | awk 'match($0,/(.)(..).(.*)/,a){$0=toupper(a[1]) a[2] "#" a[3]} 1'
Foo#ball
Cyrus' or Potong's answers are the preferred ones. (For Linux or systems with GNU sed because of \U or \u.)
This is just an additional solution with awk because you mentioned it and used also awk tag:
$ echo 'football'|awk '{a=substr($0,1,1);b=substr($0,2,2);c=substr($0,5);print toupper(a)b"#"c}'
Foo#ball
This is a most simple solution without RegEx. It will also work on non-GNU awk.
This should work with any version of awk:
awk '{
for(i=1;i<=NF;i++){
# Note that string indexes start at 1 in awk !
$i=toupper(substr($i,1,1)) "" substr($i,2,1) "#" substr($i,3)
}
print
}' file
Note: If a word is less than 3 characters long, like it, it will be printed as It#
if your data in 'd' file, tried on gnu sed:
sed -E 's/^(\w)(\w\w)\w/\U\1\E\2#/' d

Using Sed or Awk to divide a file into two based on whether a line contains a numeric value

I have used sed and awk for little while now, but I am having a challenge with the below problem. I am asking for an experienced sed/awk guru to help.
I have a file where some lines have numbers and some lines do not, like:
afjjdjfj.uihuihi
trfg.rtyhd
0rtgfd.tjbghhh
hbvfd4.rtgbvdgf
00fhfg.fdrgf
rtygfd.ijhniuh
etc.
I would like to have exactly two files out of this one, where every line is represented in one of the two files (none are deleted).
One containing all lines with any numbers 0-9 on them so given above file result would be:
0rtgfd.tjbghhh
hbvfd4.rtgbvdgf
00fhfg.fdrgf
and another file containing the rest of the lines that do not have any numbers 0-9 on them, so given the above, file it would be:
afjjdjfj.uihuihi
trfg.rtyhd
rtygfd.ijhniuh
I've tried different strategies in both sed and awk and nothing is giving me exactly what I need.
What would be the best sed or awk one liner to solve this problem?
Thank you for your time,
Tom
Easily with Awk:
awk '/[0-9]/{print > file1; next} {print > file2}' inputfile
With single GNU sed command:
sed -ne '/[0-9]/w with_digits.txt' -e '//!w no_digits.txt' input
Results:
> cat no_digits.txt
afjjdjfj.uihuihi
trfg.rtyhd
rtygfd.ijhniuh
> cat with_digits.txt
0rtgfd.tjbghhh
hbvfd4.rtgbvdgf
00fhfg.fdrgf
w filename Write the pattern space to filename.
If you don't mind running twice over the input, you can use just grep:
grep '[0-9]' input > with_digits
grep -v '[0-9]' input > without_digits
perl -MFile::Slurp -lpe '/\d/ ? append_file("digits.txt",$_) : append_file("no_digits.txt",$_)' input.txt

Cut number from string

I want to cut several numbers from a .txt file to add them later up. Here is an abstract from the .txt file:
anonuser pts/25 127.0.0.1 Mon Nov 16 17:24 - crash (10+23:07)
I want to get the "10" before the "+" and I only want the number, nothing else. This number should be written to another .txt file. I used this code, but it only works if the number has one digit:
awk ' /^'anonuser' / {split($NF,k,"[(+0:)][0-9][0-9]");print k[1]} ' log2.txt > log3.txt
With GNU grep:
grep -Po '\(\K[^+]*' file > new_file
Output to new_file:
10
See: PCRE Regex Spotlight: \K
What if you use the match() function in awk?
$ awk '/^anonuser/ && match($NF,/^\(([0-9]*)/,a) {print a[1]}' file
10
How does this work?
/^anonuser/ && match() {print a[1]} if the line starts with anonuser and the pattern is found, print it.
match($NF,/^\(([0-9]*)/,a) in the last field ((10+23:07)), look for the string ( + digits and capture these in the array a[].
Note also that this approach allows you to store the values you capture, so that you can then sum them as you indicate in the question.
The following uses the same approach as the OP, and has a couple of advantages, e.g. it does not require anything special, and it is quite robust (with respect to assumptions about the input) and maintainable:
awk '/^anonuser/ {split($NF,k,/+/); gsub(/[^0-9]/,"",k[1]); print k[1]}'
for anything more complex use awk but for simple task sed is easy enough
sed -r '/^anonuser/{s/.*\(([0-9]+)\+.*/\1/}'
find the number between a ( and + sign.
I am not sure about the format in the file.
Can you use simple cut commands?
cut -d"(" -f2 log2.txt| cut -d"+" -f1 > log3.txt

Pick a specific value in a program output (Bash)

I'm running LIBSVM in linux terminal called by a C program. Ok, i need to pick the output but the format is the following
Accuracy = 80% (24/30) (classification)
I need to pick only the "80" value as an integer. I tried with sed and came to this command:
sed 's/[^0-9^'%']//g' 'f' >> f
This is filtering all integers in the output and, thus, isn't working yet, so I need help. Thanks in advance
Try grep in PCRE mode (-P), printing only the matched parts (-o), with a lookahead assertion:
$ echo "Accuracy = 80% (24/30) (classification)" | grep -Po '[0-9]+(?=%)'
80
The regexp:
[0-9] # match a digit
+ # one or more times
(?=%) # assert that the digits are followed by a %
It is very trivial with awk. Identify the column you need and strip the '%' sign from it. The /^Accuracy/ regex ensures that the action is only performed on the lines starting with Accuracy. You don't need it if your file only contains one line.
awk '/^Accuracy/{sub(/%/,"");print $3}' inputFile
Alternatively, you can set space and % as field separators and do
awk -F'[ %]' '/^Accuracy/{print $3}' inputFile
If you want to do it with sed then you can try something like:
sed '/^Accuracy/s/.* \(.*\)%.*/\1/' inputFile
This might work for you (GNU sed):
sed -nr '/^Accuracy = ([^%]*)%.*/s//\1/p' file

How to display the first word of each line in my file using the linux commands?

I have a file containing many lines, and I want to display only the first word of each line with the Linux commands.
How can I do that?
You can use awk:
awk '{print $1}' your_file
This will "print" the first column ($1) in your_file.
Try doing this using grep :
grep -Eo '^[^ ]+' file
try doing this with coreutils cut :
cut -d' ' -f1 file
I see there are already answers. But you can also do this with sed:
sed 's/ .*//' fileName
The above solutions seem to fit your specific case. For a more general application of your question, consider that words are generally defined as being separated by whitespace, but not necessarily space characters specifically. Columns in your file may be tab-separated, for example, or even separated by a mixture of tabs and spaces.
The previous examples are all useful for finding space-separated words, while only the awk example also finds words separated by other whitespace characters (and in fact this turns out to be rather difficult to do uniformly across various sed/grep versions). You may also want to explicitly skip empty lines, by amending the awk statement thus:
awk '{if ($1 !="") print $1}' your_file
If you are also concerned about the possibility of empty fields, i.e., lines that begin with whitespace, then a more robust solution would be in order. I'm not adept enough with awk to produce a one-liner for such cases, but a short python script that does the trick might look like:
>>> import re
>>> for line in open('your_file'):
... words = re.split(r'\s', line)
... if words and words[0]:
... print words[0]
...or on Windows (if you have GnuWin32 grep) :
grep -Eo "^[^ ]+" file

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