How do I change the value of a specific column in Unix?

How do I change a particular column value in awk Unix?

Type the following awk command:

  1. awk ‘{ gsub(“,”,””,$3); print $3 }’ /tmp/data.txt.
  2. awk ‘BEGIN{ sum=0} { gsub(“,”,””,$3); sum += $3 } END{ printf “%.2fn”, sum}’ /tmp/data.txt.
  3. awk ‘{ x=gensub(“,”,””,”G”,$3); printf x “+” } END{ print “0” }’ /tmp/data.txt | bc -l.

How do you change a value to another value in Unix?

Replace Text in Single File

  1. -i = edit the file “in-place” – sed will directly modify the file if it finds anything to replace.
  2. s = substitute the following text.
  3. hello = what you want to substitute.
  4. hello_world = what you want to replace.
  5. g = global, match all occurrences in the line.

How do I select a specific column in Unix?

The syntax for extracting a selection based on a column number is:

  1. $ cut -c n [filename(s)] where n equals the number of the column to extract. …
  2. $ cat class. A Johnson Sara. …
  3. $ cut -c 1 class. A. …
  4. $ cut -f n [filename(s)] where n represents the number of the field to extract. …
  5. $ cut -f 2 class > class.lastname.

How do I cut a specific column in Linux?

cut command in Linux with examples

  1. -b(byte): To extract the specific bytes, you need to follow -b option with the list of byte numbers separated by comma. …
  2. -c (column): To cut by character use the -c option. …
  3. -f (field): -c option is useful for fixed-length lines.

How do you replace a word with another in Unix?

The procedure to change the text in files under Linux/Unix using sed:

  1. Use Stream EDitor (sed) as follows:
  2. sed -i ‘s/old-text/new-text/g’ input. …
  3. The s is the substitute command of sed for find and replace.
  4. It tells sed to find all occurrences of ‘old-text’ and replace with ‘new-text’ in a file named input.

What is NR in AWK command?

NR is a AWK built-in variable and it denotes number of records being processed. Usage : NR can be used in action block represents number of line being processed and if it is used in END it can print number of lines totally processed. Example : Using NR to print line number in a file using AWK.

How do you replace multiple words in Linux?


  1. i — replace in file. Remove it for a dry run mode;
  2. s/search/replace/g — this is the substitution command. The s stands for substitute (i.e. replace), the g instructs the command to replace all occurrences.

What does $# mean in shell script?

$# is the number of arguments, but remember it will be different in a function. $# is the number of positional parameters passed to the script, shell, or shell function. This is because, while a shell function is running, the positional parameters are temporarily replaced with the arguments to the function.

How do I find the 5th column in Unix?

How to do it…

  1. To print the fifth column, use the following command: $ awk ‘{ print $5 }’ filename.
  2. We can also print multiple columns and insert our custom string in between columns. For example, to print the permission and filename of each file in the current directory, use the following set of commands:

How do I select a column in Linux?

10 Practical Linux Cut Command Examples to Select File Columns

  1. Select Column of Characters. …
  2. Select Column of Characters using Range. …
  3. Select Column of Characters using either Start or End Position. …
  4. Select a Specific Field from a File. …
  5. Select Multiple Fields from a File. …
  6. Select Fields Only When a Line Contains the Delimiter.

How do you cut the first column in Unix?

To show you an example of the cut command with tab delimiter, we need to first change our delimiter from “:” to tab, for that we can use the sed command, which will replace all colon with t or tab character. After that, we can use, and then we will apply the cut command of Linux to extract the first column.

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