Login or Register to Ask a Question and Join Our Community


UNIX for Dummies Questions & Answers

Setting shell variables with ":" syntax

 
Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers Setting shell variables with ":" syntax
# 1  
Old 02-15-2010
Setting shell variables with ":" syntax
I nedd help on the below highlited one.

can any one explain on this,How its work in shell scripting.. then that will be very great full...

Code:
L_ABCD=${L_DBG:=N}

Thanks
Muddasas
Last edited by Scott; 02-15-2010 at 12:12 PM.. Reason: Code tags
# 2  
Old 02-15-2010
If L_DBG is not set , give it the value N otherwise use its value so 2 cases:

not set:
Code:
 L_ABCD=${N}

set:
Code:
L_ABCD=${L_DBG}

# 3  
Old 02-16-2010
Can u explain me what is the use of ":=" with inthe braces

Quote:
Originally Posted by vbe
If L_DBG is not set , give it the value N otherwise use its value so 2 cases:

not set:
Code:
 L_ABCD=${N}

set:
Code:
L_ABCD=${L_DBG}

# 4  
Old 02-16-2010
To give a default value to variable if variable is unset...
 
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Bash script - Print an ascii file using specific font "Latin Modern Mono 12" "regular" "9"

Hello. System : opensuse leap 42.3 I have a bash script that build a text file. I would like the last command doing : print_cmd -o page-left=43 -o page-right=22 -o page-top=28 -o page-bottom=43 -o font=LatinModernMono12:regular:9 some_file.txt where : print_cmd ::= some printing... (1 Reply)
Discussion started by: jcdole
1 Replies

2. HP-UX

HP-UX: Shell Script giving " 0^J30: Syntax error"

Hi All, We are getting a very unique error while running a shell script on HP-UX box. Can somebody help in this regards? The shell script is working fine on linux/solaris box. Error: ++++++++++++++++++++++++ $/test.sh ./test.sh: 0^J30: Syntax error $ ++++++++++++++++++++++++ TIA.... (16 Replies)
Discussion started by: vai_sh
16 Replies

3. Shell Programming and Scripting

Expect Script - Variables are Empty immediately after "Setting" Them?

Hello All, I have embedded some expect code inside a Bash script I'm writing, but for some reason any variable I 'set' to something is showing as empty immediately on the next line... I haven't run into this problem before so I'm not sure what it could be...? I'm guessing it has something to... (4 Replies)
Discussion started by: mrm5102
4 Replies

4. Shell Programming and Scripting

awk command to replace ";" with "|" and ""|" at diferent places in line of file

Hi, I have line in input file as below: 3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL My expected output for line in the file must be : "1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL" Can someone... (7 Replies)
Discussion started by: shis100
7 Replies

5. Shell Programming and Scripting

Question about special variables: "-" and "$_"

both ksh/bash support this 2 special variables, Is there any document for reference? 1) "-" is $OLDPWD 2) "$_" is last argument of previous command. (4 Replies)
Discussion started by: honglus
4 Replies

6. Shell Programming and Scripting

Command Character size limit in the "sh" and "bourne" shell

Hi!!.. I would like to know what is maximum character size for a command in the "sh" or "bourne" shell? Thanks in advance.. Roshan. (1 Reply)
Discussion started by: Roshan1286
1 Replies

7. UNIX for Advanced & Expert Users

Command Character size limit in the "sh" and "bourne" shell

Hi!!.. I would like to know what is maximum character size for a command in the "sh" or "bourne" shell? Thanks in advance.. Roshan. (1 Reply)
Discussion started by: Roshan1286
1 Replies

8. UNIX for Dummies Questions & Answers

Command Character size limit in the "sh" and "bourne" shell

Hi!!.. I would like to know what is maximum character size for a command in the "sh" or "bourne" shell? Thanks in advance.. Roshan. (1 Reply)
Discussion started by: Roshan1286
1 Replies

9. AIX

"too big" and "not enough memory" errors in shell script

Hi, This is odd, however here goes. There are several shell scripts that run in our production environment AIX 595 LPAR m/c, which has sufficient memory 14GB (physical memory) and horsepower 5CPUs. However from time to time we get the following errors in these shell scripts. The time when these... (11 Replies)
Discussion started by: jerardfjay
11 Replies

10. UNIX for Dummies Questions & Answers

No utpmx entry: you must exec "login" from lowest level "shell"

Hi I have installed solaris 10 on an intel machine. Logged in as root. In CDE, i open terminal session, type login alex (normal user account) and password and i get this message No utpmx entry: you must exec "login" from lowest level "shell" :confused: What i want is: open various... (0 Replies)
Discussion started by: peterpan
0 Replies
Login or Register to Ask a Question