How to create my own function in awk? 2

[tikual]

I have created a function in my awk script as follows:

function fun_display() {
for (i=1;i<=PageOne;i++)
if (menupage ~ /^A/)
print substr(menupage,3)
}
I use it to display the line when it starts from &quot;A&quot; letter.

After reading my learning book, it shown that I can insert few variables in ( ) sign. So I tried as follows:

function fun_display(letter) {
for (i=1;i<=PageOne;i++)
if (menupage ~ /^letter/)
print substr(menupage,3)
}

But it didn't work. So how to make my own function? Do anyone can give me an example?

Another question, where can I find awk script example from web? Because I really confused in field one &quot;$1&quot; and the shell parameter &quot;also $1&quot;. When I tried to write my awk script, I would not sure my script treats it as field one or shell parameter.

Thanks!


tikual

 

[PHV]

Try this:code
function fun_display(letter ,i) {
for (i=1;i<=PageOne;i++)
if (menupage ~ &quot;^&quot;letter)
print substr(menupage,3)
}[/code]
Note: The i isn't a parameter but a local variable

Hope This Help
PH.

 

[PHV]

Sory for the typo
Try this:

function fun_display(letter  ,i) {
for (i=1;i<=PageOne;i++)
if (menupage ~ &quot;^&quot;letter)
print substr(menupage,3)
}

Note: The i isn't a parameter but a local variable

Hope This Help
PH.

 

[tikual]

Thanks PHV,

But I don't know how to use it. I tried as follows:

Actually I call this function in BEGIN{} once. So the original one is
BEGIN {
.
.
fun_display()
}

Then I use your code but nothing to be printed. And now my code is like these:
.
.
fun_display(i)
}

i=A <---is it necessary??
function fun_display(letter ,i) {
for (i=1;i<=PageOne;i++)
if (menupage ~ &quot;^&quot;letter) <--why use &quot;^&quot;, mine not work?
print substr(menupage,3)
}

what's wrong to me?? I can print the line start from letter &quot;A&quot; if I don't use variable. Just want to know how to assign variable. Thanks again!!

tikual

 

[aigles]

function fun_display(letter ,i) {
for (i=1;i<=PageOne;i++) # <- Why this loop ?
if (menupage ~ &quot;^&quot;letter)
print substr(menupage,3)
}
BEGIN {
.
.
fun_display(&quot;A&quot
# Other way
Initiale=&quot;A&quot;
fun_display(Initiale)
}

Jean Pierre.

 

[PHV]

And this ?

function fun_display(letter  ,i) {
   for (i=1;i<=PageOne;i++)  # <- Why this loop ?
      if (menupage[i] ~ &quot;^&quot;letter)
         print substr(menupage,3)
}
BEGIN {
   .
   .
   fun_display(&quot;A&quot;)
}

Hope This Help
PH.

 

[tikual]

ok, let all of you see my draft script first.

#!/bin/awk -f
BEGIN {
FS=&quot;!!&quot;
while ((getline < &quot;menu.list&quot > 0){
++PageOne
menupage[PageOne]=$0
++count[$1]
}
fun_display()
}

function fun_display() {
for (i=1;i<=PageOne;i++)
if (menupage ~ /^A/)
print substr(menupage,3)
print &quot;&quot;
printf &quot;Enter your choice: \n&quot;
}


The following is my menu list.

A List Local Information -->
A List Network Information -->
A List Status -->
A Quit
B Local Information Page -->
B List Hostname!!uname -a
B List HostID!!hostid
B View VMstat!!vmstat
B View IOstat!!iostat
B View Swap Space!!free
B View Error Logs!!dmesg
B View User List!!more /etc/passwd
B View User Group!!more /etc/group
B Backup to Main Page

When I try the code as:

.
.
fun_display()
}

function fun_display() {
for (i=1;i<=PageOne;i++)
if (menupage ~ /^A/)
.
.
.

Result:
List Local Information -->
List Network Information -->
List Status -->
Quit

Enter your choice:

But, if I use both of your suggestion, the result is:

Enter your choice:

No list found. Anyway, I will try again when I back to home. Thanks all!!

tikual

 

[PHV]

#!/bin/awk -f
BEGIN {
FS="!!"
while ((getline < &quot;menu.list&quot;) > 0){
        ++PageOne
        menupage[PageOne]=$0
        ++count[$1]
}
fun_display(&quot;A&quot;)
}

function fun_display(letter  ,i) {
  for (i=1;i<=PageOne;i++)
    if (menupage[i] ~ &quot;^&quot;letter)
      print substr(menupage,3)
  print &quot;&quot;
  printf &quot;Enter your choice: \n&quot;
}

Hope This Help
PH.

 

[aigles]

Note you can do the same thing without awk:

grep '^A' menu.list | cut -c3-
echo &quot;\nEnter your choice : &quot;

It's possible to define a function in your script shell (sh, bash, ksh) :

DisplayMenu() {
grep &quot;^${1:-A}&quot; menu.list | cut -c3-
echo &quot;\nEnter your choice :&quot;
}

If you want to display a menu :

DisplayMenu # Display default Menu &quot;A&quot;
DisplayMenu A # Menu A
DisplayMenu B # Menu B

Jean Pierre.

 

[tikual]

Thanks both of your non-stop support! And now I know that /^.../ not works in 'if' condition.

Aigles, thanks for your reminder. Just self-learning of awk to do the menu.

Both got a star!

tikual

 

[CaKiwi]

Hey PHV,

Congratulations on being chosen Tipmaster of the Week!

CaKiwi

 

[vgersh99]

PHV,
congrats and keep on postin'!

vlad
+----------------------------+
| #include<disclaimer.h> |
+----------------------------+

 

[PC888]

PHV the tip-master of the week,
Your posts are enlightening and your follow-up on the questions is very much appreciated.
Félicitations.

 

[aigles]

Hi PHV,

Toutes mes félicitations pour cette distinction méritée.

Jean Pierre.

 

[PHV]

Thanks all guys.
I'm very glad to have the ability to help.