Posts Tagged ‘manual’

bash commands

November 12th, 2010

1. for loop

for (( EXP1; EXP2; EXP3 ))
do
	command1
	command2
	command3
done

eg:

#!/bin/bash
for (( i=0; i<5; i++ ))
do
	echo "Hello $i..."
done

2. if / else / fi statements

basic grammar (note the spaces between the [ ]):

if [ EXP ]; then
	statements...
else
	statements 2...
fi

eg:

step=5
alpha=$(echo "scale=1; $step/10" | bc)
if [ $(echo "$alpha<1" | bc) -eq 1 ]; then
	alpha=0$alpha
fi

2.1 Arithmetic Comparisons

-lt <
-gt >
-le <=
-ge >=
-eq ==
-ne !=

2.2 String Comparisons

= equal
!= not equal
< less then
> greater then
-n s1 string s1 is not empty
-z s1 string s1 is empty

3. real number calculation

(echo "scale=2; EXP" | bc)

where scale=2 sets the number of the digits after decimal point.
eg1:

a=1;b=2;
c=$(echo "scale=2; $a/$b" | bc)
echo $c

output:

.50

eg2:

exp="1223/234";
d=$(echo "scale=2; ${exp}" | bc)
echo $d

output:

5.22

reference: http://linuxconfig.org/Bash_scripting_Tutorial

4. functions

basic grammar:

function div() {
    STATEMENTS
    return XXX
}>
NOTE: A bash function can only return a number. There is no way to return directly a string. So we need to use $() to capture the result outputted in the function body.
eg:
# ----------------------------------------------
# return $1/$2 with 1 digit after decimal point.
# ----------------------------------------------
function div() {
   res=$(echo "scale=1; $1/$2" | bc)
   if [ $(echo "$res<1" | bc) -eq 1 ]; then
      res=0$res
   fi
   echo $res
}
# use the function
step=5
alpha=$(div $step 10)

Zend Framework (>=1.8) Step By Step

January 18th, 2010

Index:

  • environment set-up: eclipse / pdt / xDebug
  • quick start: zend.com / akrabat.com
  • zend application
  • db
  • auth / acl
  • router
  • session
  • module
  • ajax
  • cache
  • captcha / file
  • mail
  • test
  • performance
  • server clusters

Books and references: