Login or Register to Ask a Question and Join Our Community


Shell Programming and Scripting

OR operator syntax question in AWK script

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting OR operator syntax question in AWK script
# 1  
Old 04-24-2010
OR operator syntax question in AWK script
Hi guys,

I confused about syntax used in OR script as follow:

I have this sample file separated by "|" containing:
Code:
January|Month No. 1
February|Month No. 2
March|Month No. 3
April|Month No. 4
May|Month No. 5
June|Month No. 6
July|Month No. 7
August|Month No. 8
September|Month No. 9
October|Month No. 10
November|Month No. 11
December|Month No. 12

And I´m excluding 6 lines containing the first 6 months with this awk script (and works fine):
Code:
awk 'BEGIN {OFS=FS="|"; IGNORECASE=1} $1 !~ /january|february|march|april|may|june/' file

July|Month No. 7
August|Month No. 8
September|Month No. 9
October|Month No. 10
November|Month No. 11
December|Month No. 12

The problem is when I try to write the same one-line command in 2 or more lines, because I get errors, I mean:
Code:
awk 'BEGIN {OFS=FS="|"; IGNORECASE=1} $1 !~ /january|february|
march|april|may|june/' file

awk: BEGIN {OFS=FS="|"; IGNORECASE=1} $1 !~ /january
awk:                                         ^ unterminated regexp
awk: cmd. line:1: |february|march|april|may|june/
awk: cmd. line:1: ^ syntax error


What I´m doing wrong? how can I fix it?

* I try to do this because in the real file I need to exclude more than 20 patterns from a column and the one-line command becomes too long.

Any help would be appreciated.

Thanks.
# 2  
Old 04-24-2010
add '\' at end

Quote:
#awk 'BEGIN {OFS=FS="|"; IGNORECASE=1} $1 !~ /january|february| \
> march|april|may|june/' 1.txt
July|Month No. 7
August|Month No. 8
September|Month No. 9
October|Month No. 10
November|Month No. 11
December|Month No. 12

Thanks,
penchal
# 3  
Old 04-24-2010
Hey penchal,

Many thanks, the magic character "\" was missing for me, great to know now.

One more question regarding this:

Independently and without use what I have in other columns, how can
I replace a field value in specific line using AWK?

Inputfile (In 3rd column all lines contain the same pattern)
Code:
January|Month No. 1|Normal month
February|Month No. 2|Normal month
March|Month No. 3|Normal month
April|Month No. 4|Normal month
May|Month No. 5|Normal month
June|Month No. 6|Normal month
July|Month No. 7|Normal month
August|Month No. 8|Normal month
September|Month No. 9|Normal month
October|Month No. 10|Normal month
November|Month No. 11|Normal month
December|Month No. 12|Normal month

I would like to replace only the first and last line in column 3 as follow:
Code:
January|Month No. 1|First month
February|Month No. 2|Normal month
March|Month No. 3|Normal month
April|Month No. 4|Normal month
May|Month No. 5|Normal month
June|Month No. 6|Normal month
July|Month No. 7|Normal month
August|Month No. 8|Normal month
September|Month No. 9|Normal month
October|Month No. 10|Normal month
November|Month No. 11|Normal month
December|Month No. 12|Last month

I´m not sure how to use the "if" and "and" conditions together. I´m trying for the first part with this code, but the result is not what I need, because this script replaces all ocurrences:
Code:
awk 'BEGIN {OFS=FS="|"; IGNORECASE=1} {if($3 && NR=1) sub(/Normal month/,"First month",$3); print}' inputfile

January|Month No. 1|First month
February|Month No. 2|First month
March|Month No. 3|First month
April|Month No. 4|First month
May|Month No. 5|First month
June|Month No. 6|First month
July|Month No. 7|First month
August|Month No. 8|First month
September|Month No. 9|First month
October|Month No. 10|First month
November|Month No. 11|First month
December|Month No. 12|First month

Then, how can I replace values for first and last lines within same AWK script?

Maybe somebody could help me with this.

Thanks in advance.
# 4  
Old 04-24-2010
Something like this?
Code:
awk -F"|" '/Jan/{$3="First month"} /Dec/{$3="Last month"}1' OFS="|" file

# 5  
Old 04-24-2010
Hi Franklin,

Thanks for your reply. This works, but is there a way to force awk to see
in specific line and column?

I think something like and IF statement similar to
Code:
if($3 && NR=1) 
{code to replace string}
print $0


I ask in this way because the content in other columns different to column 3 is variable depending the file I´m processing.

Thanks in advance.
# 6  
Old 04-24-2010
Code:
nawk -F'|' 'FNR==1{$NF="somethingElse";prev=$0}{print prev;prev=$0}END{match(prev, "[^|][|]*$"); print substr(prev,1,RSTART-1) OFS "somethingElse"}' OFS='|' myFile

# 7  
Old 04-24-2010
Thanks verseg for your help.

I´ve tested and the output It´s almost complete, but it looks that
modifies the second line and last line in different way.

*I´ve used AWK instead nawk, my cygwin doesn´t know nawk.

Code:
awk -F'|' 'FNR==1{$NF="First month";prev=$0}{print prev;prev=$0}END{match(prev, "[^|][|]*$"); print substr(prev,1,RSTART-1) OFS "Last month"}' OFS='|' Dzdi_temp

January|Month No. 1|First month
January|Month No. 1|First month --> 2nd line was modified
February|Month No. 2|Normal month
March|Month No. 3|Normal month
April|Month No. 4|Normal month
May|Month No. 5|Normal month
June|Month No. 6|Normal month
July|Month No. 7|Normal month
August|Month No. 8|Normal month
September|Month No. 9|Normal month
October|Month No. 10|Normal month
November|Month No. 11|Normal month
December|Month No. 12|Normal month|Last month-->Added a new column without replace


How to fix this?

Thanks again
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Getting syntax error with awk ternary operator

split($7,a," "); date = a; time = a split(date,d,"/"); month = sprintf("%02d",d); day = sprintf("%02d",d); year = 2000 + d % 100 split(time,t,":"); hour=t; min=t hour >= 12? { hour=hour-12; amPm=" PM" } : amPM=" AM" hour == 0? hour=12 time=sprintf("%02d",hour)":"sprintf("%02d",min)amPm ... (4 Replies)
Discussion started by: Michael Stora
4 Replies

2. Shell Programming and Scripting

syntax question in regards to nested awk statements

Hello all, I am writing up an input file and I was hoping I could get some guidance as to how to best consolidate these 2 awk statements for 1 while loop. Here's my input file # cat databases.lst #NOTE: These entries are delimited by tabs "\t" #oracleSID name/pass # db11 ... (2 Replies)
Discussion started by: Keepcase
2 Replies

3. UNIX for Dummies Questions & Answers

syntax error: invalid arithmetic operator

hi, i have a bash script that i want to receive a a string from another bash file. But because the string has a dot in the middle it gives me an error. The error is in this line: let valor=$1 and the value passed is rules.txt the error is: let: valor=rules.txt: syntax error: invalid... (2 Replies)
Discussion started by: limadario
2 Replies

4. Shell Programming and Scripting

awk syntax question

Hi I use awk command to delete the first blanc line of a file: awk '/^$/ && !f{f=1;next}1' infile > outfile can somebody please explain me what the last "1'" in !f{f=1;next}1' stands for... Thansk a lot -A (3 Replies)
Discussion started by: aoussenko
3 Replies

5. Shell Programming and Scripting

zsh ternary operator syntax help

Hi, Can someone give me an example of how to use zsh's ternary operator? I tried: # a=1 # c=( a ? "true" : "false" ) and got: zsh: no matches found: ? I'm running zsh 4.2 on RHEL AS 4. Thanks! Paul (1 Reply)
Discussion started by: paul99
1 Replies

6. Shell Programming and Scripting

syntax error in shell test: unknown operator

Hi All, can some one figure out the syntax issue here. How to overcome this? #!/bin/sh $ HFR_MAIL=NO $ PRP_MAIL=NO $ MC_MAIL=NO $ if && && ]; then > echo "NO " > else > echo "YES" > fi test: unknown operator NO $ if && && ]; then > echo "NO" > else > echo "YES" >... (4 Replies)
Discussion started by: shellscripter
4 Replies

7. Shell Programming and Scripting

syntax error: `-a' unexpected operator/operand in IF

When i tyr this, it gives me a syntax error...i tried removing quotes,removing spaces,replacing -eq with '='.. Can somebody suggest that is the problem? if ]; then (4 Replies)
Discussion started by: dba.admin2008
4 Replies

8. UNIX for Dummies Questions & Answers

AWK syntax question

Hi, Have to check file names in some given directory. SO, What is the right syntax here: *$3*=="'$object_list'" - just wanted to check if $3 is in the object_list. And also, Do I need so many quotes around? (5 Replies)
Discussion started by: Leo_NN
5 Replies

9. Shell Programming and Scripting

yet another awk field syntax question

I am trying to print the remaing fields and field numbers beginning with a field 'xyz' #cat abc test1:test2:xyz:test3:test4:test5 #cat def test1:test2:test3:xyz:test4:test5 desired output is to be able to print NF and any trailing fields separated by':' test3 3 or test4 3 or test5... (4 Replies)
Discussion started by: prkfriryce
4 Replies

10. Shell Programming and Scripting

awk syntax question

Hi there could someone explain what is happening in the following function/statement for me, im just a little confused code = 'BEGIN{FS=","} { printf ("%-11s,%s%s%s,%07.2f,%14s,%-3s\n",$1,substr($2,9,2),substr($2,6,2),substr($ 2,3,2),$9,$10,$12) } this function is called later in the... (2 Replies)
Discussion started by: hcclnoodles
2 Replies
Login or Register to Ask a Question