Pick a specific value in a program output (Bash) - linux

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

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

Linux Bash: extracting text from file int variable

I haven't found anything that clearly answers my question. Although very close, I think...
I have a file with a line:
# Skipsdata for serienummer 1158
I want to extract the 4 digit number at the end and put it into a variable, this number changes from file to file so I can't just search for "1158". But the "# Skipsdata for serienummer" always remains the same.
I believe that either grep, sed or awk may be the answer but I'm not 100 % clear on their usage.
Using Awk as
numberRequired=$(awk '/# Skipsdata for serienummer/{print $NF}' file)
printf "%s\n" "$numberRequired"
1158
You can use grep with the -o switch, which prints only the matched part instead of the whole line.
Print all numbers at the end of lines from file yourFile
grep -Po '\d+$' yourFile
Print all four digit numbers at the end of lines like described in your question:
grep -Po '^# Skipsdata for serienummer \K\d{4}$' yourFile
-P enables perl style regexes which support \d and especially \K.
\d matches any digit (0-9).
\d{4} matches exactly four digits.
\K lets grep forget the previously matched part, such that only the part afterwards is printed.
There are multiple ways to find your number. Assuming the input data is in a file called inputfile:
mynumber=$(sed -n 's/# Skipsdata for serienummer //p' <inputfile) will print only the number and ignore all the other lines;
mynumber=$(grep '^# Skipsdata for serienummer' inputfile | cut -d ' ' -f 5) will filter the relevant lines first, then only output the 5th field (the number)

How to use grep and sed in order to replace the substring after searching some specific string?

I want to know how to use two 'grep' and 'sed' utilities or something else in order to replace the substring. I will explain what I want to do below.
We have the file 'test.txt' with the following string:
A1='AA1', A2='AA2', A3='AA3', A4='AA4', A5{ATTR}='AA5', A6='keyword_A'
After searching 'keyword_A' using grep, I want to replace the value of A5 with other string, for example, "NEW".
A1='AA1', A2='AA2', A3='AA3', A4='AA4', A5{ATTR}='NEW', A6='keyword_A'
I tried to use two commands like
grep keyword_A test.txt | sed -e 's/blabla/blabla/'
After trying all I know, I gave up at all.
Please let me know the right solution.
First, you never need grep and sed. Sed has a full regular-expression search engine, so it is a superset of grep. This command will read test.txt, change the lines that you've indicated, and print the entire result on standard output:
sed "/keyword_A/s/A5{ATTR}='[A-Z0-9]*'/A5{ATTR}='NEW'/g" < test.txt
If you want to store the results back into the file test.txt, use the -i (in-place editing) switch to sed:
sed "/keyword_A/s/A5{ATTR}='[A-Z0-9]*'/A5{ATTR}='NEW'/g" -i.bak test.txt
If you want to select only the indicated lines, modify those, and print only those lines to standard out, use a combination of the p (print) command and the -n (no output) switch.
sed "/keyword_A/s/A5{ATTR}='[A-Z0-9]*'/A5{ATTR}='NEW'/gp" -n test.txt
Using grep+sed is always the wrong approach. Here's one way to do it with GNU awk:
$ awk '/keyword_A/{ $0=gensub(/(A5({[^}]+})?=\047)[^\047]+/,"\\1NEW",1) } 1' file
A1='AA1', A2='AA2', A3='AA3', A4='AA4', A5{ATTR}='NEW', A6='keyword_A'
Using a couple variables you could define the keyword and replacement ( if they change at all ):
q="keyword_A"
r="NEW"
Then with sed:
sed -r "s/^(.+\{.+\}=')(.+)('.+"${q}".+)$/\1"${r}"\3/" file
Result:
A1='AA1', A2='AA2', A3='AA3', A4='AA4', A5{ATTR}='NEW', A6='keyword_A'
A5="NEW"
A6="keyword_A"
# with sed
sed "s/='[^']*\(',[[:blank:]]*A6='${A6}'\)/='${A5}\1/" YourFile
# with awk
awk -F "'" -v A5="${A5}" -v A6="${A6}" '
BEGIN { OFS="\047" }
$12 == A6 { $10 = A5; $0 = $0 }
7
' YourFile
Change by the end of the string, for sed and using ' as field separator in awk instead of traditional space.
assuming there is no ' in value (or need to treat the escaping method) for awk version
We can just directly replace the fifth column when the sting keyword_A is found as shown below:
awk -F, 'BEGIN{OFS=",";}/keyword_A/{$5="A5{ATTR}='"'"NEW"'"'"}1' filename
Couple of slight alternatives:
sed -r "/keyword_A/s/(A5[^']*')[^']*/\1NEW/"
awk -F"'" '/keyword_A/{$10 = "NEW"}1' OFS="'"
Of course the negative with awk is afterwards you would have to rename the new file.

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

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