How to do a if else match on pattern in awk

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i tried the below command: awk '/search-pattern/ {print $1}' How do i write the else part for the above command ?


Classic way:

awk '{if ($0 ~ /pattern/) {then_actions} else {else_actions}}' file

$0 represents the whole input record.

Another idiomatic way based on the ternary operator syntax selector ? if-true-exp : if-false-exp

awk '{print ($0 ~ /pattern/)?text_for_true:text_for_false}'
awk '{x == y ? a[i++] : b[i++]}'

awk '{print ($0 ~ /two/)?NR "yes":NR "No"}' <<<$'one two\nthree four\nfive six\nseven two'
1yes
2No
3No
4yes

4 Awk If Statement Examples ( if, if else, if else if, :? ), Similarly action can be performed if the condition is false. Conditional statement starts with the keyword called 'if'. Awk supports two different kind� The -F option in awk is used to specify the delimiter. It is needed here since we are going to work on the specific columns which can be retrieved only when the delimiter is known. 5. The above pattern match will also match if the first column contains "Rents".


A straightforward method is,

/REGEX/ {action-if-matches...} 
! /REGEX/ {action-if-does-not-match}

Here's a simple example,

$ cat test.txt
123
456
$ awk '/123/{print "O",$0} !/123/{print "X",$0}' test.txt
O 123
X 456

Equivalent to the above, but without violating the DRY principle:

awk '/123/{print "O",$0}{print "X",$0}' test.txt

This is functionally equivalent to awk '/123/{print "O",$0} !/123/{print "X",$0}' test.txt

When using awk /pattern/ { print "text"} /patern/ {print ""} is there an , It's a good idea to use printf instead of print for the job which you're wanting to do on match. awk '{ if (/^R1/) { printf("=> %s\n", $0) } else if (/^R2/)� Awk Else Statement While using if else conditional statements we may need to specify default condition where it will met if none of the other condition is met. We can it else and put to the end of the if-else if block. Syntax is like below


The default action of awk is to print a line. You're encouraged to use more idiomatic awk

awk '/pattern/' filename
#prints all lines that contain the pattern.
awk '!/pattern/' filename
#prints all lines that do not contain the pattern.
# If you find if(condition){}else{} an overkill to use
awk '/pattern/{print "yes";next}{print "no"}' filename
# Same as if(pattern){print "yes"}else{print "no"}

Matching Patterns and Processing Information with awk, When awk finds a pattern that matches the record, it performs the associated Problems can occur when you use an if or while statement to locate an array� Expressions as Patterns. Any awk expression is valid as an awk pattern. Then the pattern matches if the expression's value is non-zero (if a number) or non-null (if a string). The expression is reevaluated each time the rule is tested against a new input record.


Depending what you want to do in the else part and other things about your script, choose between these options:

awk '/regexp/{print "true"; next} {print "false"}'

awk '{if (/regexp/) {print "true"} else {print "false"}}'

awk '{print (/regexp/ ? "true" : "false")}'

Regex within IF statement in awk - UNIX and Linux Forums, I want to include an IF within an awk code with a regex in the following way. hello I want to do a pattern match for string in the if statement, but I am not sure� to only print the second column if it matches the pattern "yyy", you could do something like this: awk '$2 ~ /yyy/ {print $2}' asdf.txt Note that this will also match basically any line where the second column has a "yyy" in it, like these: xxx yyyz zzz xxx zyyyz


This command will check whether the values in the $1 $2 and $7-th column are greater than 1, 2, and 5.

!IF! the values do not mach they will be ignored by the filter we declared in awk.

(You can use logical Operators and = "&&"; or= "||".)

awk '($1 > 1) && ($2 > 1) && ($7 > 5)

You can monitoring your system with the "vmstat 3" command, where "3" means a 3 second delay between the new values

vmstat 3 | awk '($1 > 1) && ($2 > 1) && ($7 > 5)'

I stressed my computer with 13GB copy between USB connected HardDisks, and scrolling youtube video in Chrome browser.

Awk If, If Else , Else Statement or Conditional Statements – POFTUT, For example we can check the age of the person and act accordingly if over 60 or below 60 . Example Data. During learning awk if- if else� A straightforward method is, /REGEX/ {action-if-matches} ! /REGEX/ {action-if-does-not-match} Equivalent to the above, but without violating the DRY principle: This is functionally equivalent to awk '/123/ {print "O",$0} !/123/ {print "X",$0}' test.txt.


Expression Patterns (The GNU Awk User's Guide), The pattern matches if the expression's value is nonzero (if a number) or non-null as $1 , the value depends directly on the new input record's text; otherwise, in a pattern can be constant regular expressions, comparisons, or any other awk � This chapter describes the awk command, a tool with the ability to match lines of text in a file and a set of commands that you can use to manipulate the matched lines. In addition to matching text with the full set of extended regular expressions described in Chapter 1, awk treats each line, or record, as a set of elements, or fields, that can be manipulated individually or in combination.


AWK Language Programming, As you have already seen, each awk statement consists of a pattern with an associated action. This chapter Expression Patterns: Any expression can be used as a pattern. The pattern matches when the input record matches the regexp. Create a awk file named if_elseif.awk with the following code to print the favorite color of each person whose name exists in the file. If-elseif statement is used in the script to do this task. The script will read the first field value of the file, employee.txt and check with a particular value.


[PDF] grep, awk and sed – three VERY useful command-line utilities Matt , probably be much more useful to you if the lines identified which line in the only operates on lines that match that pattern, otherwise it operates on all lines. These. 'pattern-matching' commands can contain regular expressions as for grep.