Braindump

Bash Single Quotes

Braindump.BashSingleQuotes History

Hide minor edits - Show changes to output

January 17, 2010, at 02:16 PM by 83.77.90.209 -
Changed lines 3-4 from:
'''Wrong''': @@$ echo 'The Hitchhiker\'s Guide to the Galaxy'@@ -- Won't work, as //within single quotes the escape is disabled//.
'''Richtig''': @@$ echo 'The Hitchhiker'\''s Guide to the Galaxy'@@ -- You have to first end the string (to re-enable escaping), then write the single quote and then get continue with your string.
to:
!!! The wrong way

@@$ echo 'The Hitchhiker\'s Guide to the Galaxy'@@

This won't work, as //escaping is disabled within single quotes//.

!!! The right way

@@$ echo 'The Hitchhiker'\''s Guide to the Galaxy'@@

You have to first end the string (to re-enable escaping), then write the single quote and then continue with your string.
Changed lines 23-28 from:
'''Great use case''': Replace @@\'@@ through @@''@@ when converting MySQL scripts to Oracle SQL using @@sed@@: @@sed 's/\\'\''/'\'\''/' foo.sql@@
to:
!!! Great use case

Replace @@\'@@ through @@[=''=]@@ when converting MySQL scripts to Oracle SQL using @@sed@@:

@@sed 's/\\'\''/'\'\''/' foo.sql@@
January 17, 2010, at 02:06 PM by 83.77.90.209 -
Added lines 1-21:
!! Using single quotes inside of strings that are enclosed in single quotes

'''Wrong''': @@$ echo 'The Hitchhiker\'s Guide to the Galaxy'@@ -- Won't work, as //within single quotes the escape is disabled//.
'''Richtig''': @@$ echo 'The Hitchhiker'\''s Guide to the Galaxy'@@ -- You have to first end the string (to re-enable escaping), then write the single quote and then get continue with your string.
[@
$ echo 'The Hitchhiker'\''s Guide to the Galaxy'
The Hitchhiker's Guide to the Galaxy
$ # For the interpreter this looks as follows:
$ echo 'The Hitchhiker'\
> \'\
> 's Guide to the Galaxy'
@]

'''Great use case''': Replace @@\'@@ through @@''@@ when converting MySQL scripts to Oracle SQL using @@sed@@: @@sed 's/\\'\''/'\'\''/' foo.sql@@
[@
$ # Proof / Test for the call to sed:
$ echo "SELECT * FROM books WHERE title='The Hitchhiker\\'s Guide to the Galaxy'"
SELECT * FROM books WHERE title='The Hitchhiker\'s Guide to the Galaxy'
$ echo "SELECT * FROM books WHERE title='The Hitchhiker\\'s Guide to the Galaxy'" | sed 's/\\'\''/'\'\''/'
SELECT * FROM books WHERE title='The Hitchhiker''s Guide to the Galaxy'
@]