I need some help with BASH scripts.

BoB4ik · 12-19-2007, 03:23 PM

I'm new to Linux (i have latest Ubuntu version), i need to write 2 bash scripts for my OS subject in university, but because I'm new to this, i don't know "how to" well.
Situation:
I need 2 scripts for Library, one, which name is "jauns" cad add an entry to the Library file, another, which name "mekle" is a search script, that should be able to search the library in 2 ways - 1) by name, 2)by number of book pages.
The Library file has 5 columns - Book name, Author, Publisher, Year of publishing, Book pages (in my script they are Nosaukums Autors Izdevnieciba Gads Lappuses correspondingly(its in Latvian)).
Here is the 1 script's code - jauns:

Code:

if [ "$#" != "5" ]
then 

echo Nepareizs argumentu skaits.

echo Lai izveidotu ierakstu,  ievadiet argumentus sekojosa seciba:

echo Nosaukums Autors Izdevnieciba Gads Lappuses

echo Piemeeram - Kapitanskaja Doch Pushkin Strela 1886 356

exit

else

echo -e "$1\t$2\t$3\t$4\t$5" >>bibliteka

echo Pievienots ieraksts:

echo -e "$1\t$2\t$3\t$4\t$5\t$6\t$7"

fi

This one seems to work, but it has some minor things i don't understand.
Why if i enter 5 words with space between them, it does nothing, if I enter 4 or 6-7 it puts the entry in the Library file?

The main problem is the 2 script, here it is- mekle:

Code:

if [ "$1" = "1" ]

then

echo Meklesana pec nosaukuma:

grep "^$2" biblioteka

exit

fi

if [ "$1" = "2" ] 

then

echo Meklesana pec lappusem:

grep "^.*	.*	.*	.*	$2" biblioteka

exit

fi

echo Jusu ievade ir nederiga.

echo Pirmais arguments norada pec ka ir jamekle:

echo 1=meklet pec nosaukuma

echo 2=meklet pec lappusem

echo Otrais arguments ir meklejama vertiba

echo Piemeram: mekle 1 Tutepatas

When I run it from Terminal (/path/mekle) it gives me

Code:

./mekle: line 19: syntax error: unexpected end of file

What should i do, what did i do wrong? Please help me, I will have my exam on Friday.

Mara · 12-19-2007, 04:21 PM

Moved: This thread is more suitable in Programming and has been moved accordingly to help your thread/question get the exposure it deserves.

David1357 · 12-19-2007, 04:29 PM

Quote:

Originally Posted by BoB4ik

This one seems to work, but it has some minor things i don't understand.
Why if i enter 5 words with space between them, it does nothing, if I enter 4 or 6-7 it puts the entry in the Library file?

This script worked properly for me.

Quote:

Originally Posted by BoB4ik

When I run it from Terminal (/path/mekle) it gives me

Code:

./mekle: line 19: syntax error: unexpected end of file

What should i do, what did i do wrong? Please help me, I will have my exam on Friday.

This script also worked for me.

Do you have "#!/bin/bash" as your first line? That will probably help a lot.

jschiwal · 12-19-2007, 04:34 PM

I copied and pasted your first script and tested it myself. It worked. I tried 5 inputs and they were entered into the file separated with tabs. With 4, the lines you gave were echoed to the screen. I don't understand what your problem is with it.

BoB4ik · 12-19-2007, 04:37 PM

The very strange thing that just happened, I still don't know why, though... I've just recopied(last time a did copy/paste from my mekle file to this thread) the source code from my previous thread. Edited the mekle file with Kate editor, the text code ended up there the same as it was, but with a empty line between each line that contains text. And it worked.

Anybody knows why?
Thanks all of you, you made me copy paste it again, and it worked, because of that.

chrism01 · 12-19-2007, 06:10 PM

Just FYI, in your if statements you are comparing strings because you've got "value", but to compare numbers as numbers, you use a different set of operators: -eq, -ne ... etc
Bookmark & read this http://www.tldp.org/LDP/abs/html/com...l#EQUALSIGNREF

BoB4ik · 12-20-2007, 02:48 AM

Thanks, i'll bookmark that.

jlinkels · 12-20-2007, 06:23 AM

What language is that? I don't mean Bash, but that what is written in your own language.

jlinkels

danex50 · 12-20-2007, 08:34 AM

he said that:

Quote:

its in Latvian

David1357 · 12-20-2007, 10:29 AM

Quote:

Originally Posted by BoB4ik

Anybody knows why?

You probably edited your scripts on a Windows machine and then ran them on a Linux machine. Bash probably saw 0x0Ds in your file and crapped out. When you pasted them here, the 0x0Ds were converted to 0x0As. When you copied your scripts from here and pasted them back, bash saw no 0x0Ds and was able to run your scripts.

The moral of this story is to use a real editor if you are going to create scripts on a Windows machine. Notepad or whatever you are using is brain damaged.

Disillusionist · 12-20-2007, 05:06 PM

Quote:

unexpected end of file

Normally means that there was a block of code that was being opened but wasn't being closed

Maybe an if statement was missing the relating fi closing statement (or the closing fi was contained within a string)

Looking at the code, I can't see any reason for it, and the code works on my system.

However I would suggest using quotes when using echo statements.

I would also suggest using a case statement, example:

Code:

case $1 in
   1) echo "Meklesana pec nosaukuma:"
      grep "^$2" biblioteka;;

   2) echo "Meklesana pec lappusem:"
      grep "^.*	.*	.*	.*	$2" biblioteka;;

   *) echo "Jusu ievade ir nederiga."
      echo "Pirmais arguments norada pec ka ir jamekle:"
      echo "1=meklet pec nosaukuma"
      echo "2=meklet pec lappusem"
      echo "Otrais arguments ir meklejama vertiba"
      echo "Piemeram: mekle 1 Tutepatas";;

esac

This will run different blocks of code based on the value of $1.

To enter a book title with more than one word you would also need to use quotes:

./jauns "Essential Systems Administration 2nd Edition" "AEleen Frisch" OReily 1995 758