1st yr Exam revision thread - Scripts, C, Commands
Hello, I have an exam for 1st year Linux and Unix programming coming up in a week and I need some help going over the past exams, I want to make sure I'm getting the right answers in the past exams to ensure full marks.
The internet is a distraction so making this thread will hopefully help me focus! Also, it will be good revision for anyone else in the same boat, while hopfully helping me commit it to memory and understand it better, and the questions should be pretty easy
1. Write a bash script for the minimum program that works as follows:
Code:
$ min 2 3
The minimum of 2 and 3 is 2
Heres my answer:
Code:
#!/bin/bash
if
$1 < $2
echo "The minimum of $1 and $2 is $1"
else
echo "The minimum of $1 and $2 is $2"
fi
Pseudocode:
If
arg1 is less than arg2
output: "the minimum of arg1 and arg2 is arg1"
else
output: "the minimum of arg1 and arg2 is arg2"
Is my algorithm correct? The program compiles, but when I run it I get syntax error. What is the correct syntax please help.
---------- Post updated at 11:13 AM ---------- Previous update was at 10:43 AM ----------
Figured it out
Code:
if
[[ "$1" < "$2" ]];
then
echo "The minimum of $1 and $2 is $1"
else
echo "The minimum of $1 and $2 is $2"
fi
It works and outputs correctly. Do you think this answer would get full marks in an exam?
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Discussion started by: gurudewa
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LEARN ABOUT REDHAT
logfile
LOGFILE(1) mrtg LOGFILE(1)NAME
logfile - description of the mrtg-2 logfile format
SYNOPSIS
This document provides a description of the contents of the mrtg-2 logfile.
OVERVIEW
The logfile consists of two main sections. A very short one at the beginning:
The first Line
It stores the traffic counters from the most recent run of mrtg
The rest of the File
Stores past traffic rate averates and maxima at increassing intervals
The first number on each line is a unix time stamp. It represents the number of seconds since 1970.
DETAILS
The first Line
The first line has 3 numbers which are:
A (1st column)
A timestamp of when MRTG last ran for this interface. The timestamp is the number of non-skip seconds passed since the standard UNIX
"epoch" of midnight on 1st of January 1970 GMT.
B (2nd column)
The "incoming bytes counter" value.
C (3rd column)
The "outgoing bytes counter" value.
The rest of the File
The second and remaining lines of the file 5 numbers which are:
A (1st column)
The Unix timestamp for the point in time the data on this line is relevant. Note that the interval between timestamps increases as you
prograss through the file. At first it is 5 minutes and at the end it is one day between two lines.
This timestamp may be converted in EXCEL by using the following formula:
=(x+y)/86400+DATE(1970,1,1)
you can also ask perl to help by typing
perl -e 'print scalar localtime(x),"
"'
x is the unix timestamp and y is the offset in seconds from UTC. (Perl knows y).
B (2nd column)
The average incoming transfer rate in bytes per second. This is valid for the time between the A value of the current line and the A
value of the previous line.
C (3rd column)
The average outgoing transfer rate in bytes per second since the previous measurement.
D (4th column)
The maximum incoming transfer rate in bytes per second for the current interval. This is calculated from all the updates which have
occured in the current interval. If the current interval is 1 hour, and updates have occured every 5 minutes, it will be the biggest 5
minute transferrate seen during the hour.
E (5th column)
The maximum outgoing transfer rate in bytes per second for the current interval.
AUTHOR
Butch Kemper <kemper@bihs.net> and Tobias Oetiker <oetiker@ee.ethz.ch>
3rd Berkeley Distribution 2.9.17 LOGFILE(1)
05-25-2013
