escape character for 'psql -c ' command
Hi,
How do I escape both " and ' to be used in the 'psql -c ' command ?
For example, how to make the psql command {\copy "Table" from
'txt_file'} to be used in the psql with -c option (psql -c) ?
The "Table" has to be double quoted here.
Thanks,
Gary
Short answer: for simple commands, you can use shell-escaping of a
double-quoted string.
psql -c "\\copy \"Table\" from 'text file'"
Note: double \\ is intentional. You need to escape the backslash, which
normally escapes other special characters, like $ and ". Watch out for other
special characters though, which is why I prefer the long answer...
Long answer: A *nix shell will concatenate string literals that are
immediately following each other, even when they aren't the same type
(single quoted or double quoted). So the following:
"abc"'def'hij" (reads: double quote, abc, double quote, single quote, def,
single quote, double quote, hij, double quote)
is "abc" + 'def' + "hij" or "abcdefhij" to the shell
So if you have a single-quoted string, to insert a single quote you (1) stop
the single quoted string (2) start a double-quoted string (3) write a single
quote as the content of the double-quoted string (4) stop the double-quoted
string (5) restart the single quoted string. All without any spaces (unless
they are inside either the double or single quoted strings as part of your
content).
You can obviously insert 2 consecutive single quotes within a single
double-quoted string - or any characters... just be aware you are in
double-quotes now, so you need to escape special characters or go back to
single quotes.
Your example:
psql -c ' Copy "Table" from '"'"'text file'"'"
Derrick
On Mon, Nov 15, 2010 at 6:17 PM, Gary Fu <gfu@sigmaspace.com> wrote:
Show quoted text
Hi,
How do I escape both " and ' to be used in the 'psql -c ' command ?
For example, how to make the psql command {\copy "Table" from 'txt_file'}
to be used in the psql with -c option (psql -c) ?
The "Table" has to be double quoted here.Thanks,
Gary--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
On 11/15/10 21:10, Derrick Rice wrote:
Short answer: for simple commands, you can use shell-escaping of a
double-quoted string.psql -c "\\copy \"Table\" from 'text file'"
This works on sh, but I tried this syntax on tcsh, it fails:
11:38am 72 gfu@modular:~/sybase2postgres> psql -c "\\copy \"Table\" from
'text file'"
Unmatched ".
How to make it work on tcsh ?
Thanks,
Gary
Show quoted text
Note: double \\ is intentional. You need to escape the backslash, which
normally escapes other special characters, like $ and ". Watch out for
other special characters though, which is why I prefer the long answer...Long answer: A *nix shell will concatenate string literals that are
immediately following each other, even when they aren't the same type
(single quoted or double quoted). So the following:"abc"'def'hij" (reads: double quote, abc, double quote, single quote,
def, single quote, double quote, hij, double quote)is "abc" + 'def' + "hij" or "abcdefhij" to the shell
So if you have a single-quoted string, to insert a single quote you (1)
stop the single quoted string (2) start a double-quoted string (3) write
a single quote as the content of the double-quoted string (4) stop the
double-quoted string (5) restart the single quoted string. All without
any spaces (unless they are inside either the double or single quoted
strings as part of your content).You can obviously insert 2 consecutive single quotes within a single
double-quoted string - or any characters... just be aware you are in
double-quotes now, so you need to escape special characters or go back
to single quotes.Your example:
psql -c ' Copy "Table" from '"'"'text file'"'"
Derrick
On Mon, Nov 15, 2010 at 6:17 PM, Gary Fu <gfu@sigmaspace.com
<mailto:gfu@sigmaspace.com>> wrote:Hi,
How do I escape both " and ' to be used in the 'psql -c ' command ?
For example, how to make the psql command {\copy "Table" from
'txt_file'} to be used in the psql with -c option (psql -c) ?
The "Table" has to be double quoted here.Thanks,
Gary--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org
<mailto:pgsql-general@postgresql.org>)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
Please include the list when replying.
On Tue, Nov 16, 2010 at 11:45 AM, Gary Fu <gfu@sigmaspace.com> wrote:
Short answer: for simple commands, you can use shell-escaping of a
double-quoted string.
psql -c "\\copy \"Table\" from 'text file'"
This works on sh, but I tried this syntax on tcsh, it fails:
11:38am 72 gfu@modular:~/sybase2postgres> psql -c "\\copy \"Table\" from
'text file'"
Unmatched ".How to make it work on tcsh ?
Consult your shell's documentation.
http://www.tcsh.org/tcsh.html/Lexical_structure.html
http://www.tcsh.org/tcsh.html/Special_shell_variables.html#backslash_quote
Apparently you can use "set backslash_quote=1" and then the original will
work. Read the warning above about backslash_quote:
Or use the long-version, which is pretty reliable.
Derrick