How do you print a common line in two files in UNIX?

How do I list a common line in two files in UNIX?

Use comm -12 file1 file2 to get common lines in both files. You may also needs your file to be sorted to comm to work as expected. Or using grep command you need to add -x option to match the whole line as a matching pattern. The F option is telling grep that match pattern as a string not a regex match.

How do I print a specific line in Unix?

Write a bash script to print a particular line from a file

  1. awk : $>awk ‘{if(NR==LINE_NUMBER) print $0}’ file.txt.
  2. sed : $>sed -n LINE_NUMBERp file.txt.
  3. head : $>head -n LINE_NUMBER file.txt | tail -n + LINE_NUMBER Here LINE_NUMBER is, which line number you want to print. Examples: Print a line from single file.

How do you join two files line by line in Unix?

To merge files line by line, you can use the paste command. By default, the corresponding lines of each file are separated with tabs. This command is the horizontal equivalent to the cat command, which prints the content of the two files vertically.

How do you find the common lines between two large files?

When you have more than 2 files, iterate over one file and build a new trie from the matches.

  1. Sort just 1 file (#1).
  2. Walk through each line of the next file (#2) and do a binary search on the #1 file (based on the number of lines).
  3. If you find the string; write it on another temp file (#temp1).

How do you find duplicate lines in Unix?

The uniq command in UNIX is a command line utility for reporting or filtering repeated lines in a file. It can remove duplicates, show a count of occurrences, show only repeated lines, ignore certain characters and compare on specific fields.

How do I print the difference between two files in UNIX?

The different file comparison commands used in Unix are cmp, comm, diff, dircmp, and uniq.

  1. Unix Video #8:
  2. #1) cmp: This command is used to compare two files character by character.
  3. #2) comm: This command is used to compare two sorted files.
  4. #3) diff: This command is used to compare two files line by line.

How do I show the first 10 lines of a file in Linux?

Type the following head command to display first 10 lines of a file named “bar.txt”:

  1. head -10 bar.txt.
  2. head -20 bar.txt.
  3. sed -n 1,10p /etc/group.
  4. sed -n 1,20p /etc/group.
  5. awk ‘FNR <= 10’ /etc/passwd.
  6. awk ‘FNR <= 20’ /etc/passwd.
  7. perl -ne’1..10 and print’ /etc/passwd.
  8. perl -ne’1..20 and print’ /etc/passwd.

How do cats last 10 lines?

To look at the last few lines of a file, use the tail command. tail works the same way as head: type tail and the filename to see the last 10 lines of that file, or type tail -number filename to see the last number lines of the file.

How do I display the 10th line of a file?

Below are three great ways to get the nth line of a file in Linux.

  1. head / tail. Simply using the combination of the head and tail commands is probably the easiest approach. …
  2. sed. There are a couple of nice ways to do this with sed . …
  3. awk. awk has a built in variable NR that keeps track of file/stream row numbers.

How do you join lines in Unix?

The join command in UNIX is a command line utility for joining lines of two files on a common field. Suppose you have two files and there is a need to combine these two files in a way that the output makes even more sense.

How do I combine two files in UNIX?

Replace file1 , file2 , and file3 with the names of the files you wish to combine, in the order you want them to appear in the combined document. Replace newfile with a name for your newly combined single file.

How do you convert multiple lines to one line in Unix?

Simply put, the idea of this sed one-liner is: append each line into the pattern space, at last replace all line breaks with the given string.

  1. :a; – we define a label called a.
  2. N; – append next line into sed’s pattern space.
  3. $! …
  4. s/n/REPLACEMENT/g – replace all line breaks with the given REPLACEMENT.

How do I list old files in Linux?

To find files that are at least 24 hours old, use -mtime +0 or (m+0) . If you want to find files that were last modified yesterday or before, you can use find with the -newermt predicate: find -name ‘*2015*’ !

How do you compare two text files line by line in Python?

Approach

  1. Open both files in read mode.
  2. Store list of strings.
  3. Start comparing both files with the help of intersection() method for common strings.
  4. Compare both files for differences using while loop.
  5. Close both files.

How can I find the difference between two text files in Linux?

9 Best File Comparison and Difference (Diff) Tools for Linux

  1. diff Command. …
  2. Vimdiff Command. …
  3. Kompare. …
  4. DiffMerge. …
  5. Meld – Diff Tool. …
  6. Diffuse – GUI Diff Tool. …
  7. XXdiff – Diff and Merge Tool. …
  8. KDiff3 – – Diff and Merge Tool.
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