sed to read one file and delete pattern in second file - bash

I have a list of users that have logged in during the past 180 days and a list of total users from LDAP. Each list is within text file and each name is on its own line. With sed or awk can I have a script read from current-users.txt and delete from total-users.txt to give me a text document that has all of the inactive accounts for the past 180 days?
Thanks in advance!


No need to sed or awk, grep suffices:
grep -vf current-users.txt total-users
It returns all the lines that are in total_users but not in current-users.txt.
grep -f gets parameters from a file.
grep -v inverts the result.
Example
$ cat total_users
one
two
three
four
$ cat some_users
two
four
$ grep -vf some_users total_users
one
three


Using awk
awk 'NR==FNR{a[$1];next} !($1 in a)' current_users total_users

Related

replace different text in different lines using sed

I need to do the following:
I have two files, the first one contains only the lines that are going to be modified:
1
2
3
and the second contains the text that is going to be replaced in original file (final_output.txt)
13e
19f
16a
the original file is
wire1: 0x'd318
wire2: 0x'd415
wire3: 0x'd362
I want to get the following:
wire1: 0x13e
wire2: 0x19f
wire3: 0x16a
This is only a part of final_output.txt, because the file can contain at least 100 lines, and I pretend to do it using for, but I don't know how to implement it

awk to the rescue!
assuming the part after the single quote will be replaced.
$ awk -v q="'" 'NR==FNR {a[$1]=$2;next}
FNR in a {sub(q".*",a[FNR])}1' <(paste index rep) file
index is the index file, rep is the replacement file, and file is the original data file.

Another solution where file1 contains only the lines, file2 contains the text that is going to be replaced in original file and final_output.txt contains your original text.
for ((i=1;i<=$(wc -l < file1);i++)); do sed -i "$(sed -n "${i}p" file1)s#$(sed -n "$(sed -n "${i}p" file1)p" final_output.txt | grep -oP "'.*")#$(sed -n "${i}p" file2)#g" final_output.txt; done
Output
darby#Debian:~/Scrivania$ cat final_output.txt
wire1: 0x13e
wire2: 0x19f
wire3: 0x16a
darby#Debian:~/Scrivania$

Compare 2 csv files and delete rows - Shell

I have a 2 csv files. One has several columns, the other is just one column with domains. Simplified data of these files would be
file1.csv:
John,example.org,MyCompany,Australia
Lenny,domain.com,OtherCompany,US
Martha,site.com,ThirdCompany,US
file2.csv:
example.org
google.es
mysite.uk
The output should be
Lenny,domain.com,OtherCompany,US
Martha,site.com,ThirdCompany,US
I have tried this solution
grep -v -f file2.csv file1.csv >output-file
Found here
http://www.unix.com/shell-programming-and-scripting/177207-removing-duplicate-records-comparing-2-csv-files.html
But since there is no explanation whatsoever about how the script works, and I suck at shell, I cannot tweak it to make it work for me
A solution for this would be highly appreciated, a solution with some explanation would be awesome! :)
EDIT:
I have tried the line that was suppose to work, but for some reason it does not. Here the output from my terminal. What's wrong with this?
Desktop $ cat file1.csv ; echo
John,example.org,MyCompany,Australia
Lenny ,domain.com,OtherCompany,US
Martha,mysite.com,ThirCompany,US
Desktop $ cat file2.csv ; echo
example.org
google.es
mysite.uk
Desktop $ grep -v -f file2.csv file1.csv
John,example.org,MyCompany,Australia
Lenny ,domain.com,OtherCompany,US
Martha,mysite.com,ThirCompany,US
Why grep doesn't remove the line
John,example.org,MyCompany,Australia

The line you posted, works just fine.
$ grep -v -f file2.csv file1.csv
Lenny,domain.com,OtherCompany,US
Martha,site.com,ThirdCompany,US
And here's an explanation. grep will search for a given pattern in a given file and print all lines that match. The simplest example of usage is:
$ grep John file1.csv
John,example.org,MyCompany,Australia
Here we used a simple pattern that matches each character, but you can also use regular expressions (basic, extended, and even perl-compatible ones).
To invert the logic, and print only the lines that do not match, we use the -v switch, like this:
$ grep -v John file1.csv
Lenny,domain.com,OtherCompany,US
Martha,site.com,ThirdCompany,US
To specify more than one pattern, you can use the option -e pattern multiple times, like this:
$ grep -v -e John -e Lenny file1.csv
Martha,site.com,ThirdCompany,US
However, if there is a larger number of patterns to check for, we might use the -f file option that will read all patterns from a file specified.
So, when we combine all of those; reading patterns from a file with -f and inverting the matching logic with -v, we get the line you need.

One in awk:
$ awk -F, 'NR==FNR{a[$1];next}($2 in a==0)' file2 file1
Lenny,domain.com,OtherCompany,US
Martha,site.com,ThirdCompany,US
Explained:
$ awk -F, ' # using awk, comma-separated records
NR==FNR { # process the first file, file2
a[$1] # hash the domain to a
next # proceed to next record
}
($2 in a==0) # process file1, if domain in $2 not in a, print the record
' file2 file1 # file order is important

grep matching specific position in lines using words from other file

I have 2 file
file1:
12342015010198765hello
12342015010188765hello
12342015010178765hello
whose each line contains fields at fixed positions, for example, position 13 - 17 is for account_id
file2:
98765
88765
which contains a list of account_ids.
In Korn Shell, I want to print lines from file1 whose position 13 - 17 match one of account_id in file2.
I can't do
grep -f file2 file1
because account_id in file2 can match other fields at other positions.
I have tried using pattern in file2:
^.{12}98765.*
but did not work.

Using awk
$ awk 'NR==FNR{a[$1]=1;next;} substr($0,13,5) in a' file2 file1
12342015010198765hello
12342015010188765hello
How it works
NR==FNR{a[$1]=1;next;}
FNR is the number of lines read so far from the current file and NR is the total number of lines read so far. Thus, if FNR==NR, we are reading the first file which is file2.
Each ID in in file2 is saved in array a. Then, we skip the rest of the commands and jump to the next line.
substr($0,13,5) in a
If we reach this command, we are working on the second file, file1.
This condition is true if the 5 character long substring that starts at position 13 is in array a. If the condition is true, then awk performs the default action which is to print the line.
Using grep
You mentioned trying
grep '^.{12}98765.*' file2
That uses extended regex syntax which means that -E is required. Also, there is no value in matching .* at the end: it will always match. Thus, try:
$ grep -E '^.{12}98765' file1
12342015010198765hello
To get both lines:
$ grep -E '^.{12}[89]8765' file1
12342015010198765hello
12342015010188765hello
This works because [89]8765 just happens to match the IDs of interest in file2. The awk solution, of course, provides more flexibility in what IDs to match.

Using sed with extended regex:
sed -r 's#.*#/^.{12}&/p#' file2 |sed -nr -f- file1
Using Basic regex:
sed 's#.*#/^.\\{12\\}&/p#' file1 |sed -n -f- file
Explanation:
sed -r 's#.*#/^.{12}&/p#' file2
will generate an output:
/.{12}98765/p
/.{12}88765/p
which is then used as a sed script for the next sed after pipe, which outputs:
12342015010198765hello
12342015010188765hello

Using Grep
The most convenient is to put each alternative in a separate line of the file.
You can look at this question:
grep multiple patterns single file argument list too long

Removing lines based on column values read from file

I use the following code to extract lines from input_file with a certain value in the first column. The values on which the extraction of lines is based is in "one_column.txt":
while read file
do
awk -v col="$file" '$1==col {print $0}' input_file >> output_file
done < one_column.txt
My question is, how do I extract the lines where the first column does not match any of the values in one_column.txt? In other words, how do I extract only the remaining lines from input_file that don't end up in output_file?

grep -vf can make it:
grep -vf output_file input_file
grep -f compares one file with another. grep -v matches the opposite.
Test
$ cat a
hello
good
bye
$ cat b
hello
good
bye
you
all
$ grep -f a b
hello
good
bye
$ grep -vf a b ## opposite
you
all

grep "output of cat command - every line" in a different file

Sorry title of this question is little confusing but I couldnt think of anything else.
I am trying to do something like this
cat fileA.txt | grep `awk '{print $1}'` fileB.txt
fileA contains 100 lines while fileB contains 100 million lines.
What I want is get id from fileA, grep that id in a different file-fileB and print that line.
e.g fileA.txt
1234
1233
e.g.fileB.txt
1234|asdf|2012-12-12
5555|asdd|2012-11-12
1233|fvdf|2012-12-11
Expected output is
1234|asdf|2012-12-12
1233|fvdf|2012-12-11

Getting rid of cat and awk altogether:
grep -f fileA.txt fileB.txt

awk alone can do that job well:
awk -F'|' 'NR==FNR{a[$0];next;}$1 in a' fileA fileB
see the test:
kent$ head a b
==> a <==
1234
1233
==> b <==
1234|asdf|2012-12-12
5555|asdd|2012-11-12
1233|fvdf|2012-12-11
kent$ awk -F'|' 'NR==FNR{a[$0];next;}$1 in a' a b
1234|asdf|2012-12-12
1233|fvdf|2012-12-11
EDIT
add explanation:
-F'|' #| as field separator (fileA)
'NR==FNR{a[$0];next;} #save lines in fileA in array a
$1 in a #if $1(the 1st field) in fileB in array a, print the current line from FileB
for further details I cannot explain here, sorry. for example how awk handle two files, what is NR and what is FNR.. I suggest that try this awk line in case the accepted answer didn't work for you. If you want to dig a little bit deeper, read some awk tutorials.

If the id's are on distinct lines you could use the -f option in grep as such:
cut -d "|" -f1 < fileB.txt | grep -F -f fileA.txt
The cut command will ensure that only the first field is searched for in the pattern searching using grep.
From the man page:
-f FILE, --file=FILE
Obtain patterns from FILE, one per line.
The empty file contains zero patterns, and therefore matches nothing.
(-f is specified by POSIX.)

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