Enclosing characters in single quotes preserves the literal value of each character within the quotes. A single quote may not occur between single quotes, even when preceded by a backslash.
Therefore, you need to terminate the quoted expression, insert the escaped quote, and start a new quoted expression. The shell's quote removal does not add any extra spaces, so in effect you get string concatenation.
Last edited by vidyadhar85; 09-16-2009 at 10:53 PM..
Hello, I'm trying to use grep or egrep to exclude a whole range of characters but how do I exclude both a single and a double quote.
It might be easier to say how do I use grep to find both single and double quotes.
grep ' ' " ' file
grep detects the first single quote within my... (4 Replies)
I'm not very familiar with the ssh command. When I tried to set a variable and then echo its value on a remote machine via ssh, I found a problem. For example,
$ ITSME=itsme
$ ssh xxx.xxxx.xxx.xxx "ITSME=itsyou; echo $ITSME"
itsme
$ ssh xxx.xxxx.xxx.xxx 'ITSME=itsyou; echo $ITSME'
itsyou
$... (3 Replies)
Hi,
I am trying to write the following command as an alias in my .bashrc file.
bjobs -u all | awk '{if (NR > 1) {username++;}}END{{print"\nJOBS BY USER:\n"} for (i in username) {print username,i;}{print"\n Total Jobs=",NR-1,"\n" }}'
The command simply puts how many jobs each user is... (2 Replies)
Unix superusers,
I am new to unix but would like to learn more about grep. I am very familiar with regular expressions as i have used them for searching text files in windows based text editors. Since I am not very familiar with Unix, I dont understand when one should use GREP with the... (2 Replies)
Hi Unix experts,
Believe me, this forum has been really great help and I searched for many things that were already answered before open new post that were just new versions of old one, but with this one, I just can't simply move any forward.
This must be quite easy, but I cant find where I... (1 Reply)
Hello. I'm trying to write a bash script that uses GNU screen and have hit a brick wall that has cost me many hours... (I'm sure it has something to do with quoting/globbing, which is why I post it here)
I can make a script that does the following just fine:
test.sh:
#!/bin/bash
# make... (2 Replies)
Hi i have to insert the below line into a specific line number of another file
export MBR_CNT_PRCP_TYPE_CODES_DEL="'01','02','04','05','49','55','UNK'"
I have passed the above line to a variable say ins_line. I have used below command to perform the insert
awk 'NR==3{print "'"${ins_line}"'"}1'... (1 Reply)
Hi,
Trying to change the prompt. I have the following code.
export PS1='
<${USER}@`hostname -s`>$ '
The hostname is not displayed
<abc@`hostname -s`>$ uname -a
AIX xyz 1 6 00F736154C00
<adcwl4h@`hostname -s`>$
If I use double quotes, then the hostname is printed properly but... (3 Replies)
Hi Froum.
I have tried in vain to find a solution for this problem - I'm trying to replace any double quotes within a quoted string with a single quote, leaving everything else as is.
I have the following data:
Before:
... (32 Replies)
Hi All,
I'm unable to load the data using sql loader where there are double quotes within the double quotes As these are optionally enclosed by double quotes.
Sample Data :
"221100",138.00,"D","0019/1477","44012075","49938","49938/15043000","Television - 22" Refurbished - Airwave","Supply... (6 Replies)
Perl::Critic::Policy::ValuesAndExpressions::ProhibitInteUseraContribPerl::Critic::Policy::ValuesAndExpressions::ProhibitInterpolationOfLiterals(3)NAME
Perl::Critic::Policy::ValuesAndExpressions::ProhibitInterpolationOfLiterals - Always use single quotes for literal strings.
AFFILIATION
This Policy is part of the core Perl::Critic distribution.
DESCRIPTION
Don't use double-quotes or "qq//" if your string doesn't require interpolation. This saves the interpreter a bit of work and it lets the
reader know that you really did intend the string to be literal.
print "foobar"; #not ok
print 'foobar'; #ok
print qq/foobar/; #not ok
print q/foobar/; #ok
print "$foobar"; #ok
print "foobar
"; #ok
print qq/$foobar/; #ok
print qq/foobar
/; #ok
print qq{$foobar}; #preferred
print qq{foobar
}; #preferred
Use of double-quotes might be reasonable if the string contains single quote (') characters:
print "it's me"; # ok, if configuration flag set
CONFIGURATION
The types of quoting styles to exempt from this policy can be configured via the "allow" option. This must be a whitespace-delimited
combination of some or all of the following styles: "qq{}", "qq()", "qq[]", and "qq//".
This is useful because some folks have configured their editor to apply special syntax highlighting within certain styles of quotes. For
example, you can tweak "vim" to use SQL highlighting for everything that appears within "qq{}" or "qq[]" quotes. But if those strings are
literal, Perl::Critic will complain. To prevent this, put the following in your .perlcriticrc file:
[ValuesAndExpressions::ProhibitInterpolationOfLiterals]
allow = qq{} qq[]
The flag "allow_if_string_contains_single_quote" permits double-quoted strings if the string contains a single quote (') character. It
defaults to off; to turn it on put the following in your .perlcriticrc file:
[ValuesAndExpressions::ProhibitInterpolationOfLiterals]
allow_if_string_contains_single_quote = 1
SEE ALSO
Perl::Critic::Policy::ValuesAndExpressions::RequireInterpolationOfMetachars
AUTHOR
Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>
COPYRIGHT
Copyright (c) 2005-2011 Imaginative Software Systems. All rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license
can be found in the LICENSE file included with this module.
perl v5.16.3Perl::Critic::Policy::ValuesAndExpressions::ProhibitInterpolationOfLiterals(3)