Sponsored Content
Top Forums UNIX for Beginners Questions & Answers String has * as the field delimiter and I need echo/awk to escape it, how? Post 302989024 by Scrutinizer on Friday 6th of January 2017 10:49:40 AM
Old 01-06-2017
You do not need to escape it in awk. With awk a single character field separator, that is not a space character, is not treated as a regular expression string, but as a literal character.

Quote:
An extended regular expression can be used to separate fields by assigning a string containing the expression to the built-in variable FS, either directly or as a consequence of using the -F sepstring option. The default value of the FS variable shall be a single <space>. The following describes FS behavior:

1. If FS is a null string, the behavior is unspecified.

2. If FS is a single character:
a. If FS is <space>, skip leading and trailing <blank> and <newline> characters; fields shall be delimited by sets of one or more <blank> or <newline> characters.

b. Otherwise, if FS is any other character c, fields shall be delimited by each single occurrence of c.
3. Otherwise, the string value of FS shall be considered to be an extended regular expression. Each occurrence of a sequence matching the extended regular expression shall delimit fields.
awk:regular expressions

Last edited by Scrutinizer; 01-06-2017 at 12:21 PM..
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Set a variable field delimiter using awk

How can i set a variable field delimiter using awk?? I wanna do something like this ,but i canīt get the correct syntaxis : VARI=TEST echo "0121212TESTxvcshaashd"|awk 'FS="$VARI" {print $2}' Thanks. (2 Replies)
Discussion started by: Klashxx
2 Replies

2. UNIX for Advanced & Expert Users

Printing Field with Delimiter in AWK/cut

Hello, I had posted earlier about printing fields using AWK, but now I have a slightly different problem. I have text files in the format: 1*2,3,4,5 and wish to print the first, third, and fifth fields, including the asterisk and commas. In other words, after filtering it should look... (1 Reply)
Discussion started by: Jahn
1 Replies

3. Shell Programming and Scripting

need to convert a decimal value to an ascii char with awk for the field delimiter

Hello, I need an awk script to receive a variable that's an decimal value such as 009 or 031 and then convert this value to an ascii character to use as the FS (field separator for the input file). For example, 009 should be converted to an ascii tab 031 should be converted to an ascii... (1 Reply)
Discussion started by: script_op2a
1 Replies

4. Shell Programming and Scripting

awk output field delimiter

Dear All, 1.txt (tab in between each value in a line) a b c a b c a c d you can see below, why with ~ i can output with tab, but = cannot? # awk -F'\t' '$2 ~ /b/' 1 a b c a b c # awk -F'\t' '$2 = "b"' 1 a b c a b c a b d ... (1 Reply)
Discussion started by: jimmy_y
1 Replies

5. Shell Programming and Scripting

how to find the nth field value in delimiter file in unix using awk

Hi All, I wanted to find 200th field value in delimiter file using awk.? awk '{print $200}' inputfile I am getting error message :- awk: The field 200 must be in the range 0 to 199. The source line number is 1. The error context is {print >>> $200 <<< } using... (4 Replies)
Discussion started by: Jairaj
4 Replies

6. Shell Programming and Scripting

Awk Search text string in field, not all in field.

Hello, I am using awk to match text in a tab separated field and am able to do so when matching the exact word. My problem is that I would like to match any sequence of text in the tab-separated field without having to match it all. Any help will be appreciated. Please see the code below. awk... (3 Replies)
Discussion started by: rocket_dog
3 Replies

7. Shell Programming and Scripting

perform echo and awk inside a string

hi, just wanted to make a shortcut of this one a="a b c" b=`echo $a | awk '{print $2}'` echo "the middle is $b" why can't i do this: a="a b c" echo "the middle is ${`echo $a | awk '{print $2}'`}" <- bad substitution :wall: thanks (6 Replies)
Discussion started by: h0ujun
6 Replies

8. Shell Programming and Scripting

awk :how to change delimiter without giving all field name

Hi Experts, i need to change delimiter from tab to "," sample test file cat test A0000368 A29938511 072569352 5 Any 2 for Ģ1.00 BUTCHERS|CAT FOOD|400G Sep 12 2012 12:00AM Jan 5 2014 11:59PM Sep 7 2012 12:00AM M 2.000 group 5 ... (2 Replies)
Discussion started by: Lakshman_Gupta
2 Replies

9. Shell Programming and Scripting

How can awk ignore the field delimiter like comma inside a field?

We have a csv file as mentioned below and the requirement is to change the date format in file as mentioned below. Current file (file.csv) ---------------------- empname,date_of_join,dept,date_of_resignation ram,08/09/2015,sales,21/06/2016 "akash,sahu",08/10/2015,IT,21/07/2016 ... (6 Replies)
Discussion started by: gopal.biswal
6 Replies

10. UNIX for Beginners Questions & Answers

awk Associative Array and/or Referring to Field by String (Nonconstant String Value)

I will start with an example of what I'm trying to do and then describe how I am approaching the issue. File PS028,005 Lexeme HRS # M # PhraseType 1(1:1) 7(7) PhraseLab 501 503 ClauseType ZYq0 PS028,005 Lexeme W # L> # BNH # M #... (17 Replies)
Discussion started by: jvoot
17 Replies
regex(3)						     Library Functions Manual							  regex(3)

Name
       re_comp, re_exec - regular expression handler

Syntax
       char *re_comp(s)
       char *s;

       re_exec(s)
       char *s;

Description
       The  subroutine	compiles  a string into an internal form suitable for pattern matching.  The subroutine checks the argument string against
       the last string passed to

       The subroutine returns 0 if the string s was compiled successfully; otherwise a string containing an  error  message  is  returned.  If	is
       passed 0 or a null string, it returns without changing the currently compiled regular expression.

       The  subroutine returns 1 if the string s matches the last compiled regular expression, 0 if the string s failed to match the last compiled
       regular expression, and -1 if the compiled regular expression was invalid (indicating an internal error).

       The strings passed to both and may have trailing or embedded newline characters; they are terminated by	nulls.	 The  regular  expressions
       recognized are described in the manual entry for given the above difference.

Diagnostics
       The subroutine returns -1 for an internal error.

       The subroutine returns one of the following strings if an error occurs:

       No previous regular expression
       Regular expression too long
       unmatched (
       missing ]
       too many () pairs
       unmatched )

See Also
       ed(1), ex(1), egrep(1), fgrep(1), grep(1)

																	  regex(3)
All times are GMT -4. The time now is 11:15 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy