Sponsored Content
Full Discussion: BASH quoting behavior
Top Forums Shell Programming and Scripting BASH quoting behavior Post 302272260 by radoulov on Tuesday 30th of December 2008 04:41:49 AM
Old 12-30-2008
Quote:
Originally Posted by na5m
The block below isn't a surprise:
Code:
$ ls
file1 file2 file3
$ x=*
$ echo $x
file1 file2 file3
$ echo '$x'
$x
$ echo "$x"
*
$

But I found this block a bit bewildering:
Code:
$ echo $x'
>'
*

$

I'm wondering why substitution wasn't performed on the $x, since it was unquoted (as far as I can tell).
As matrixmadhan already pointed out, It's because you're trying to match *\n (filename expansion occurs after word splitting):

Code:
bash-2.03$ ls
file1  file2  file3
bash-2.03$ x=*
bash-2.03$ echo \$x "$x" $x
$x * file1 file2 file3
bash-2.03$ echo *'
> '
*

bash-2.03$ touch 'newline_at_the_end
> '
bash-2.03$ echo $x'
'
newline_at_the_end

ls -b
file1                file2                file3                newline_at_the_end\012

 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Mimic bash history behavior

Does anyone know of a way to mimic the up arrow/down arrow type bash behavior within a shell script? Say I have a scripted menu, and would like to be able to up arrow to bring up the last X number of lines of user input? Thanks to anybody with a suggestion. :) (0 Replies)
Discussion started by: sysera
0 Replies

2. Shell Programming and Scripting

Quoting issue: Trouble with bash strings in script

I can do this on the command line: sqsh -S 192.168.x.x -o tmp -U user -P fakepass -D horizon -C "\ select second_id from borrower where btype like '%wsd%' " I can also just leave the SQL at the end intact on one line .... ... However, when I throw this in a script like: $SQSH -o... (4 Replies)
Discussion started by: Bubnoff
4 Replies

3. Shell Programming and Scripting

bash: correct quoting with find and exiv2?

Hi, I need to embed a metatag to image files which contain qrcodes, i usually do this with exiv -M "set Exif.Image.DocumentName `zbarimg -q -Sdisable -Sqrcode.enable --raw image.tif`" image.tif which works fine. However I need to do this recursivly for whole directory and subdiretory... (4 Replies)
Discussion started by: mcframe
4 Replies

4. Red Hat

BASH command not found strang behavior

Hi all I am relatively new to linux (specifically red hat). I have installed Fedora 13 on my machine and started playing with the terminal when i found a very strange behavior when typing a command that is not found: the terminal does not prompt me back. In other words, i am logged as root (or... (4 Replies)
Discussion started by: abohmeed
4 Replies

5. UNIX for Advanced & Expert Users

Different redirection behavior in BASH/Linux when run under cron vice login ???

run_xfs_fsr is a xfs filesystem maintenance script designed to run under cron. The system is a home theater personal computer running mythbuntu 10.10, and is accessed remotely for these tests. cron runs a script, (xfs_fsr.sh) at 02:30 that runs the subject script under BASH and sets the... (3 Replies)
Discussion started by: keepitsimpleeng
3 Replies

6. UNIX for Advanced & Expert Users

unexpected behavior bash, set -o vi, history -a, and HISTFILE

I am trying to get my history in sync in multiple bash sections and things aren't working the way I expect. Desired behavior, hitting esc-K in all bash sessions (same userid and machine) will use the same history. Observed behavior: Esc-k shows the history of the current session, rather than... (8 Replies)
Discussion started by: gg48gg
8 Replies

7. Shell Programming and Scripting

Tricky BASH quoting question

I have some data files that I can identify by a certain pattern in the names using find. Every one of those data files has an XML file associated with it (can be multiple data files per XML file). The XML file is always up one directory from the data file(s) in a folder calledRun##### -... (12 Replies)
Discussion started by: Michael Stora
12 Replies

8. Shell Programming and Scripting

Help with Bash quoting

I am trying to write a BASH script that will prompt a user to enter a number of days, then calculate the date. My problem is the date command uses single or double quotes. For Example.. date -d "7 days" Here is an example of some same code I am trying to work through. echo "when do you... (4 Replies)
Discussion started by: javajockey
4 Replies

9. UNIX for Advanced & Expert Users

Bash : While Loop behavior

Good Morning I think there may be something I dont understand fully. The following code works well, but I dont like the set domen method. #!/bin/bash # domen="y" while do echo " M A I N - M E N U" echo "1. Contents of /etc/passwd" echo "2. List of users currently logged" echo... (10 Replies)
Discussion started by: popeye
10 Replies

10. Shell Programming and Scripting

Different behavior between bash shell and bash script for cmd

So I'm trying to pass certain json elements as env vars and use them later on in a script. Sample json: JSON='{ "Element1": "file-123456", "Element2": "Name, of, company written in, a very weird way", "Element3": "path/to/some/file.txt", }' (part of the) script: for s... (5 Replies)
Discussion started by: da1
5 Replies
COMBINE(1)																COMBINE(1)

NAME
combine - combine sets of lines from two files using boolean operations SYNOPSIS
combine file1 and file2 combine file1 not file2 combine file1 or file2 combine file1 xor file2 _ file1 and file2 _ _ file1 not file2 _ _ file1 or file2 _ _ file1 xor file2 _ DESCRIPTION
combine combines the lines in two files. Depending on the boolean operation specified, the contents will be combined in different ways: and Outputs lines that are in file1 if they are also present in file2. not Outputs lines that are in file1 but not in file2. or Outputs lines that are in file1 or file2. xor Outputs lines that are in either file1 or file2, but not in both files. "-" can be specified for either file to read stdin for that file. The input files need not be sorted, and the lines are output in the order they occur in file1 (followed by the order they occur in file2 for the two "or" operations). Bear in mind that this means that the operations are not commutative; "a and b" will not necessarily be the same as "b and a". To obtain commutative behavior sort and uniq the result. Note that this program can be installed as "_" to allow for the syntactic sugar shown in the latter half of the synopsis (similar to the test/[ command). It is not currently installed as "_" by default, but you can alias it to that if you like. SEE ALSO
join(1) AUTHOR
Copyright 2006 by Joey Hess <joey@kitenet.net> Licensed under the GNU GPL. moreutils 2012-04-09 COMBINE(1)
All times are GMT -4. The time now is 05:38 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy