Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: evaluating variables
Top Forums UNIX for Dummies Questions & Answers evaluating variables Post 56598 by zazzybob on Wednesday 6th of October 2004 08:53:42 AM
Old 10-06-2004
Hmmm... Re-reading your question, i don't know if this'll help....

Code:
#!/usr/bin/ksh

counter=1
cmd="awk"

number_of_fields=4

while [[ $counter -le $number_of_fields ]]
do
  cmd=$cmd" -vvar$counter=\"$counter\""
  (( counter = counter + 1 ))
done

counter=1

cmd=$cmd" '{ print "
while [[ $counter -le $number_of_fields ]]
do
  cmd=$cmd"\$var$counter\" \" "
  (( counter = counter + 1 ))
done

cmd=$cmd" '} file"

eval $cmd

exit 0

But I still don't really understand the original question so your milage may vary. This code will print the first four fields of "file". It should give you a lead on the quoting necessary anyways.

Cheers
ZB
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

evaluating for a number

I apologize for the simple question but can someone please help me with how to evaluate a number? I will be reading in a file and if a number is >= 100000000, I will do something, if not, I will exit the if statement. Thanks in advance (1 Reply)
Discussion started by: hedrict
1 Replies

2. UNIX for Dummies Questions & Answers

evaluating params

Hi all, I ve a script like.... TBL=employee sql=`cat abhi.sql` \\ abhi.sql contains ------- select a from $TBL echo $TBL echo $sql SQL=`echo $sql` echo $SQL now i want SQL as select a from employee and as select a from $TBL How can I achieve this? Help appriciated (3 Replies)
Discussion started by: abzi
3 Replies

3. Shell Programming and Scripting

* character evaluating too soon - Help!

I have a user defined configuration file, which could contain the following type of entries: directory_001=/a/directory/structure pattern_001=fred* pattern_002=* I have a script which reads the file generically which will loop round loop 1 genvar=”directory” iteration=”001” ... (11 Replies)
Discussion started by: Bab00shka
11 Replies

4. UNIX for Dummies Questions & Answers

evaluating date +%m

how do i evaluate the value of date if ( $(date +%m) > 8 ) then FY_STAMP=FY$(echo $(($(date +%Y) + 1)) | cut -c3-4) else FY_STAMP=FY$(date +%y) fi i want this to make the FY_STAMP increment by 1 if the month is september and up. but cant seem to make it work (3 Replies)
Discussion started by: rsf01
3 Replies

5. Shell Programming and Scripting

Evaluating Decimal values

How can I evaluate a decimal value in an if statement? echo "Enter limit:" read limit (enter a decmal value, ie: 2.5) decimallimit=`echo $limit+0|bc|quit` echo $decimallimit if then echo $decimallimit else echo "failed" fi (4 Replies)
Discussion started by: larrys721
4 Replies

6. Shell Programming and Scripting

$$# is evaluating to 1 when no value

I have the following in my makefile: RESULT=`../${TOOLS_ROOT_PATH}/ext_tools.sh 11`; \ set $$RESULT > tMp; \ rm tMp; \ if ; then \ echo copying external-local tool: $< \($$*\); \ mkdir -p ${EXTERNAL_LOCAL_BIN_DIR}/$<; \ cp -f... (4 Replies)
Discussion started by: jake_ryan
4 Replies

7. Shell Programming and Scripting

if condition not evaluating as expected

Hi all, Thanks in advance for your time. I have a data file like this: 1 7.465753425 2 8.980821918 1 1.717808219 1 6.550684932 0 5.432876712 I wish to write a bash script to check both columns and output a 1 if col1==1 AND col2<3. Otherwise I want to output a 0. In the above... (5 Replies)
Discussion started by: jem8271
5 Replies

8. Shell Programming and Scripting

Evaluating a variable

Does anyone know of a way to force a variable name held in another variable to return the value of the first variable? Best if I give an example, that does not work: /usr/local/bin >cat mike.sh NUM1ref=16 NUM2ref=32 echo "==============" for VAR in NUM1 NUM2 do XXXX=${VAR}ref echo $XXXX... (4 Replies)
Discussion started by: mikejordan
4 Replies

9. UNIX for Dummies Questions & Answers

Comparing and Evaluating

Hi Guys, Good day ULF :) I hope you can help me again with my problem. I have a file which looks like this: Command was launched from partition 0. ------------------------------------------------ Executing command in server server3 Dec 18 21:31:12 AHM04 nseventmgr: EVENT-SET:... (4 Replies)
Discussion started by: rymnd_12345
4 Replies

10. Shell Programming and Scripting

Problem evaluating condition

First, given this bit of code (line numbers included for reference: 59 get_all_db () { 60 #echo getting all db 61 dblist=`egrep -i "product/12" /etc/oratab |grep -v "listener"|\ 62 awk -F\: '{print $1}'|sort` 63 echo list is $dblist 64 echo 65 echo 66 echo "INSTANCE_NAME ... (15 Replies)
Discussion started by: edstevens
15 Replies

LEARN ABOUT CENTOS

trace-cmd-extract

TRACE-CMD-EXTRACT(1)													      TRACE-CMD-EXTRACT(1)

NAME

       trace-cmd-extract - extract out the data from the Ftrace Linux tracer.

SYNOPSIS

       trace-cmd extract [OPTIONS]

DESCRIPTION

       The trace-cmd(1) extract is usually used after trace-cmd-start(1) and trace-cmd-stop(1). It can be used after the Ftrace tracer has been
       started manually through the Ftrace pseudo file system.

       The extract command creates a trace.dat file that can be used by trace-cmd-report(1) to read from. It reads the kernel internal ring buffer
       to produce the trace.dat file.

OPTIONS

       -p plugin
	   Although extract does not start any traces, some of the plugins require just reading the output in ASCII format. These are the latency
	   tracers, since the latency tracers have a separate internal buffer. The plugin option is therefore only necessary for the wakeup,
	   wakeup-rt, irqsoff, preemptoff and preemptirqsoff plugins.

	       With out this option, the extract command will extract from the internal
	       Ftrace buffers.

       -O option
	   If a latency tracer is being extracted, and the -p option is used, then there are some Ftrace options that can change the format. This
	   will update those options before extracting. To see the list of options see trace-cmd-list. To enable an option, write its name, to
	   disable the option append the characters no to it. For example: noprint-parent will disable the print-parent option that prints the
	   parent function in printing a function event.

       -o outputfile
	   By default, the extract command will create a trace.dat file. This option will change where the file is written to.

SEE ALSO

       trace-cmd(1), trace-cmd-record(1), trace-cmd-report(1), trace-cmd-start(1), trace-cmd-stop(1), trace-cmd-reset(1), trace-cmd-split(1),
       trace-cmd-list(1), trace-cmd-listen(1)

AUTHOR

       Written by Steven Rostedt, <rostedt@goodmis.org[1]>

RESOURCES

       git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git

COPYING

       Copyright (C) 2010 Red Hat, Inc. Free use of this software is granted under the terms of the GNU Public License (GPL).

NOTES

	1. rostedt@goodmis.org
	   mailto:rostedt@goodmis.org

								    06/11/2014						      TRACE-CMD-EXTRACT(1)
All times are GMT -4. The time now is 03:05 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy