I have a rather large file I need to split. However, I don't need the first 1000 lines. I would like to start the split at line 1001 and then continue to split the file by 1000. I know how to split by 1000, that is no problem.
CODE:
split --lines=1000 *.txt
However, I want to skip the first 1000 lines. Is there any way to do this?
Use tail -n +1001 to get lines starting from 1001st line:
cat *.txt | tail -n +1001 | split --lines=1000
#JDE876 : We can even get the desired output using perl one liner
perl -ne "print if $. > 1000" file
Related
This question might have been asked a million times before, but did’t see my exaxt case.
Suppose a text file contains:
a
ab
bac
Now I want to grep on ‘a’ and have a hit only on the 1st line. After the ‘a’ there’s always a [tab] character.
Anyone any ideas?
Thanks!
Ronald
Try this:
head -1 *.txt | grep -P "a\t"
head will give you specified amount of lines of each file (all txt files in my example) , grep -P use the regular expressions as defined by perl (perl has \t as tab)
Let's say I have f files.
From each file I want to grep a pattern.
I just want n pattern matches from each file.
What I have:
strings <files_*> | grep <pattern> | head -<n>
I do need to use strings because I'm dealing with binaries, and from this command I am only getting n lines from the total.
grep has a -mX option that allows you to specify how many matches. However, adding this to your piped command line, is going to stop at the the first X matches total... not per file.
To get per-file count, I came up with this:
for FILE in `ls -f <files_*>` ; do strings "$FILE" | grep -m<X> <pattern> ; done
Example (searching for "aa" the files that match x* and returning up to 3 lines from each would be:
for FILE in `ls -f x*` ; do strings "$FILE" | grep -m3 aa ; done
Can u pls advise the unix command as I have a file which contain the records in the below format
333434
435435
435443
434543
343536
Now the total line count is 89380 , now i want to create a seprate
I am trying to split my large big file into small bits using the line numbers. For example my file has 89380 lines and i would like to divide this into small files wach of which has 1000 lines.
could you please advise unix command to achieve this
can unix split command can be used here..!!
Use split
Syntax split [options] filename prefix
Replace filename with the name of the large file you wish to split. Replace prefix with the name you wish to give the small output files. You can exclude [options], or replace it with either of the following:
-l linenumber
-b bytes
If you use the -l (a lowercase L) option, replace linenumber with the number of lines you'd like in each of the smaller files (the default is 1,000). If you use the -b option, replace bytes with the number of bytes you'd like in each of the smaller files.
The split command will give each output file it creates the name prefix with an extension tacked to the end that indicates its order. By default, the split command adds aa to the first output file, proceeding through the alphabet to zz for subsequent files. If you do not specify a prefix, most systems use x .
Example1:
split myfile
This will output three 1000-line files: xaa, xab, and xac.
Example2:
split -l 500 myfile segment
This will output six 500-line files: segmentaa, segmentab, segmentac, segmentad, segmentae, and segmentaf.
Example3:
Assume myfile is a 160KB file:
split -b 40k myfile segment
This will output four 40KB files: segmentaa, segmentab, segmentac, and segmentad.
You can use the --lines switch or its short form -l
split --lines=1000 input_file_name output_file_prefix
I think you can use sed command.
you can use sed -n "1, 1000p" yourfile > outputfile to get line 1 to line 1000.
I have a very large set of strings, one on every line of a file. Many strings occur more than one times in the file at different locations.
I want a frequency count of the strings using unix commands like awk, grep, uniq and so on. I tried few combinations but it didn't work.
what is the exact command to get the frequency count?
To count the occurrences of lines in a file the simplest thing to do is:
$ sort file | uniq -c
I would like to compare two files [ unsorted ]
file1 and file2. I would like to do file2 - file1 [ the difference ] irrespective of the line number?
diff is not working.
I got the solution by using comm
comm -23 file1 file2
will give you the desired output.
The files need to be sorted first anyway.
Well, you can just sort the files first, and diff the sorted files.
sort file1 > file1.sorted
sort file2 > file2.sorted
diff file1.sorted file2.sorted
You can also filter the output to report lines in file2 which are absent from file1:
diff -u file1.sorted file2.sorted | grep "^+"
As indicated in comments, you in fact do not need to sort the files. Instead, you can use a process substitution and say:
diff <(sort file1) <(sort file2)
There are 3 basic commands to compare files in unix:
cmp : This command is used to compare two files byte by byte and as any mismatch occurs,it echoes it on the screen.if no mismatch occurs i gives no response.
syntax:$cmp file1 file2.
comm : This command is used to find out the records available in one but not in another
diff
Most easy way: sort files with sort(1) and then use diff(1).