Sponsored Content
Top Forums Shell Programming and Scripting How to check a variable for empty and a newline Post 302391939 by cfajohnson on Wednesday 3rd of February 2010 01:31:28 AM
Old 02-03-2010
Quote:
Originally Posted by Scrutinizer
Code:
case $var in 
  ""|*"\n"*) echo hello
esac


You are testing for a literal '\n', not a newline.

Code:
NL='
'
case $var in 
  ""|*"$NL"*) echo hello
esac

 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

How to check if two variable are empty strings at once? (bash)

I need to check if $1 or $2 are empty before continuing but I don't know if bash has any logic of the sort. This is what I'm looking for - except that "and" doesn't seem to work. if and ;then ... Thank you! :D (4 Replies)
Discussion started by: ph0enix
4 Replies

2. Shell Programming and Scripting

How to check the variable is empty with spacing

How to check the variable is empty or not? aaa=" " how to check aaa variable is empty or just spacing? If only spacing inside.. it will asume it is empty. some are 6 spacing, or 8 spacing.. as long as variable is empty with spacing.. anyone can help me? (2 Replies)
Discussion started by: ryanW
2 Replies

3. UNIX for Dummies Questions & Answers

newline character in a variable

variable="unix\nlinux" echo $variable expected output: unix linux :wall: can i do that ?? thanks in advance!! (3 Replies)
Discussion started by: sathish92
3 Replies

4. Homework & Coursework Questions

Check whether a Directory is empty or not

Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted! 1. The problem statement, all variables and given/known data: 1.pls tell me the command for checking whether a given directory is empty or not . 2. can i check what is the... (1 Reply)
Discussion started by: upvan111
1 Replies

5. Shell Programming and Scripting

How to check newline character in file?

Hi All, I have file with only one record,always be only one record. as like below. if that line contains newline end of the line..no need to add, if not just add the new line character. END OF FILE. ROW COUNT: 7 Please help me.. Thanks, (9 Replies)
Discussion started by: bmk
9 Replies

6. Shell Programming and Scripting

Check if the string is empty

I am reading from a file and executing the jobs with/without parameters as the job requires. File job1 R job2 job3 Y 123 if then <job>.ksh else <job>.ksh $params fi This works fine if the line read from the file has parameters it executes like job1.ksh R But for... (2 Replies)
Discussion started by: nw2unx123
2 Replies

7. Shell Programming and Scripting

How to check whether a variable is empty or contains some value?

hi, i want to check whether a a variable contains some value or is empty in a shell script. so if the variable contains some value i want to do some job and if the variable doesnt contain any value then i need to skip that job. here is a sample script read_filenames.sh contains ... (5 Replies)
Discussion started by: Little
5 Replies

8. Shell Programming and Scripting

Cant check empty string

Hello So i have that script collection, in which i have a single script to create a configuration file. In there, i have multiple occourences of something like this: prj_title=$(tui-read "What is the TITLE? ($prj_name):") ] && prj_title="${prj_name/_/ }" They all work as expected, if... (5 Replies)
Discussion started by: sea
5 Replies

9. Shell Programming and Scripting

Stupid question to check if variable is empty

Hi, I am simply trying to check if the variable is empty in the code below but it isn;t working. Anything that I might have missed here #Check if values in job card are not empty title=`cat $filename | grep "TITLE:" | cut -d ":" -f3` if ] then echo "10:Title Empty" ":Fail">> $rptfile... (13 Replies)
Discussion started by: nua7
13 Replies

10. Shell Programming and Scripting

Insert newline when grep result is empty

Given a csv file with 40 columns with name, address, hometown etc. I use a bash command in 1 line which: 1. gets the address column and pipes that to 2. grep the first digit and everything that follows Command: awk -F ";" '{print $19}' /Users/jb/Desktop/ReorderTempTotal.csv | grep -o "\d.*"... (7 Replies)
Discussion started by: JBVeenstra
7 Replies
getopt(1)						      General Commands Manual							 getopt(1)

NAME
getopt - parse command options SYNOPSIS
optstring args DESCRIPTION
is used to break up options in command lines for easy parsing by shell procedures and to check for legal options. optstring is a string of recognized option letters (see getopt(3C)). If a letter is followed by a colon, the option is expected to have an argument, which may or may not be separated from it by whitespace. The positional parameters ...) of the shell are reset so that each option is preceded by a and is in its own positional parameter; each option argument is also parsed into its own positional parameter. recognizes two hyphens to delimit the end of the options. If absent, places at the end of the options. The most common use of is in the shell's command (see the example below) where converts the command line to a more easily parsed form. writes the modified command line to the standard output. EXTERNAL INFLUENCES
Environment Variables determines the language in which messages are displayed. If is not specified in the environment or is set to the empty string, the value of is used as a default for each unspecified or empty vari- able. If is not specified or is set to the empty string, a default of "C" (see lang(5)) is used instead of If any internationalization variable contains an invalid setting, behaves as if all internationalization variables are set to "C". See environ(5). International Code Set Support Single-byte and multibyte character code sets are supported. DIAGNOSTICS
prints an error message on the standard error when it encounters an option letter that is not included in optstring. EXAMPLES
The following code fragment processes the arguments for a command that can take the options or and the option which requires an argument: This code accepts any of the following as equivalent: WARNINGS
option arguments must not be null strings nor contain embedded blanks. SEE ALSO
getopts(1), sh(1), getopt(3C). getopt(1)
All times are GMT -4. The time now is 03:36 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy