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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

 

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LEARN ABOUT OPENDARWIN

merge

MERGE(1)						      General Commands Manual							  MERGE(1)

NAME

       merge - three-way file merge

SYNOPSIS

       merge [ options ] file1 file2 file3

DESCRIPTION

       merge  incorporates all changes that lead from file2 to file3 into file1.  The result ordinarily goes into file1.  merge is useful for com-
       bining separate changes to an original.	Suppose file2 is the original, and both file1 and file3 are modifications of  file2.   Then  merge
       combines both changes.

       A  conflict  occurs  if	both  file1 and file3 have changes in a common segment of lines.  If a conflict is found, merge normally outputs a
       warning and brackets the conflict with <<<<<<< and >>>>>>> lines.  A typical conflict will look like this:

	      <<<<<<< file A
	      lines in file A
	      =======
	      lines in file B
	      >>>>>>> file B

       If there are conflicts, the user should edit the result and delete one of the alternatives.

OPTIONS

       -A     Output conflicts using the -A style of diff3(1), if supported by diff3.  This merges all changes leading from file2  to  file3  into
	      file1, and generates the most verbose output.

       -E, -e These  options  specify conflict styles that generate less information than -A.  See diff3(1) for details.  The default is -E.  With
	      -e, merge does not warn about conflicts.

       -L label
	      This option may be given up to three times, and specifies labels to be used in place of the corresponding  file  names  in  conflict
	      reports.	 That  is, merge -L x -L y -L z a b c generates output that looks like it came from files x, y and z instead of from files
	      a, b and c.

       -p     Send results to standard output instead of overwriting file1.

       -q     Quiet; do not warn about conflicts.  -V Print 's version number.

DIAGNOSTICS

       Exit status is 0 for no conflicts, 1 for some conflicts, 2 for trouble.

IDENTIFICATION

       Author: Walter F. Tichy.
       Manual Page Revision: 1.1.1.1; Release Date: 2002/04/30.
       Copyright (C) 1982, 1988, 1989 Walter F. Tichy.
       Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995 Paul Eggert.

SEE ALSO

       diff3(1), diff(1), rcsmerge(1), co(1).

BUGS

       It normally does not make sense to merge binary files as if they were text, but merge tries to do it anyway.

GNU
								    2002/04/30								  MERGE(1)
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