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""Help Me!""Beginner awk learning issue

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# 1  
Old 03-05-2012
""Help Me!""Beginner awk learning issue
Hi All,

I have just now started learning awk from the source - Awk - A Tutorial and Introduction - by Bruce Barnett

and the bad part is that I am stuck on the very first example for running the awk script.
The script is as -
Code:
#!/bin/sh
# Linux users have to change $8 to $9
awk '
BEGIN  { print "File\tOwner" } 
  { print $8, "\t", $3} 
END    { print " - DONE -" } 
'

However when I am saving it and running it as - "awk -f awk_example1.sh"

I am getting an error -
Code:
awk: awk_example1.sh:3: awk '
awk: awk_example1.sh:3:     ^ invalid char ''' in expression

Please can you suggest where I am getting this wrong ?
Please can anyone also suggest some good source to learn awk for a begineer ?

Thanks in advance.
Cheers!!!
# 2  
Old 03-05-2012
How do you run the above awk script..? Try like sh awk_example1.sh where
Code:
[mkt @michael]$ cat awk_example1.sh
#!/bin/sh
# Linux users have to change $8 to $9
awk '
BEGIN  { print "File\tOwner" } 
  { print $8, "\t", $3} 
END    { print " - DONE -" } 
'
[mkt @michael]$

Also post the OS your using.
This User Gave Thanks to michaelrozar17 For This Post:
csrohit
# 3  
Old 03-05-2012
Quote:
Originally Posted by csrohit
Code:
#!/bin/sh
# Linux users have to change $8 to $9
awk '
BEGIN  { print "File\tOwner" } 
  { print $8, "\t", $3} 
END    { print " - DONE -" } 
'

However when I am saving it and running it as - "awk -f awk_example1.sh"
1. What is the input to your awk statement? $8 and $3 refer to the 8th and 3rd fields of an input. But your awk doesn't know what the input is.
2. You've written the awk statement in a shell script yet you invoked it as an awk program.
3. The study material you mentioned is good enough. Read once more and you'll understand.

Copy-paste this on your command line and try to understand what's happening:
Code:
ls -l | awk 'BEGIN {print "File => Owner"} {print $9, "=>", $3} END { print "- DONE -" }'

The output of 'ls -l' is sent as input to awk which prints the 9th field followed by an arrow followed by the 3rd field.
This User Gave Thanks to balajesuri For This Post:
csrohit
# 4  
Old 03-05-2012
sh awk_example1.sh worked fine and ./awk_example1.sh too worked but the output that I am getting is just as -
Code:
File    Owner

However I am having two files in current directory.

The OS that I am using is Linux.
# 5  
Old 03-05-2012
may be you are not passing the ouput of ls -l command

Code:
$cat awk_example1.sh
#!/bin/sh
# Linux users have to change $8 to $9
ls -l | awk '
BEGIN  { print "File\tOwner" } 
  { print $8, "\t", $3} 
END    { print " - DONE -" } 
'

This User Gave Thanks to itkamaraj For This Post:
csrohit
# 6  
Old 03-05-2012
Quote:
Originally Posted by csrohit
sh awk_example1.sh worked fine and ./awk_example1.sh too worked but the output that I am getting is just as -
Code:
File    Owner

However I am having two files in current directory.
The OS that I am using is Linux.
Ok.Since you do not pass any input to awk statement you just get the output as File Owner. Try as suggested by itkamaraj or ls -l | ./awk_example1.sh
This User Gave Thanks to michaelrozar17 For This Post:
csrohit
# 7  
Old 03-05-2012
Thanks a lot...that worked..cheers!!
Quote:
Originally Posted by itkamaraj
may be you are not passing the ouput of ls -l command

Code:
$cat awk_example1.sh
#!/bin/sh
# Linux users have to change $8 to $9
ls -l | awk '
BEGIN  { print "File\tOwner" } 
  { print $8, "\t", $3} 
END    { print " - DONE -" } 
'

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