How to escape a double quote inside double quotes?

Question

Can anybody show me how to escape double quote inside a double string in bash?

For example in my shell script

#!/bin/bash

dbload="load data local infile \"'gfpoint.csv'\" into table $dbtable FIELDS TERMINATED BY ',' ENCLOSED BY '\"' LINES TERMINATED BY \"'\n'\" IGNORE 1 LINES"

I can't get the ENCLOSED BY \" with double quote escape correctly. I can't use single quote for my variable because i want to use variable $dbtable.

Answer 1

Use a backslash:

echo "\""     # Prints one " character.

Answer 2

check out printf...

#!/bin/bash
mystr="say \"hi\""

Without using printf

echo -e $mystr

output: say "hi"

Using printf

echo -e $(printf '%q' $mystr)

output: say \"hi\"

Answer 3

Bash allows you to place strings adjacently, and they'll just end up being glued together.

So this:

$ echo "Hello"', world!'

produces

Hello, world!

The trick is to alternate between single and double-quoted strings as required. Unfortunately, it quickly gets very messy. For example:

$ echo "I like to use" '"double quotes"' "sometimes"

produces

I like to use "double quotes" sometimes

---

In your example, I would do it something like this:

$ dbtable=example
$ dbload='load data local infile "'"'gfpoint.csv'"'" into '"table $dbtable FIELDS TERMINATED BY ',' ENCLOSED BY '"'"'"' LINES "'TERMINATED BY "'"'\n'"'" IGNORE 1 LINES'
$ echo $dbload

which produces the following output:

load data local infile "'gfpoint.csv'" into table example FIELDS TERMINATED BY ',' ENCLOSED BY '"' LINES TERMINATED BY "'\n'" IGNORE 1 LINES

---

It's difficult to see what's going on here, but I can annotate it using Unicode quotes. The following won't work in bash – it's just for illustration:

dbload=‘load data local infile "’“'gfpoint.csv'”‘" into’“table $dbtable FIELDS TERMINATED BY ',' ENCLOSED BY '”‘"’“' LINES”‘TERMINATED BY "’“'\n'”‘" IGNORE 1 LINES’

The quotes like “ ‘ ’ ” in the above will be interpreted by bash. The quotes like " ' will end up in the resulting variable.

If I give the same treatment to the earlier example, it looks like this:

$ echo“I like to use”‘"double quotes"’“sometimes”

Answer 4

add "\" before double quote to escape it, instead of \

#! /bin/csh -f

set dbtable = balabala

set dbload = "load data local infile "\""'gfpoint.csv'"\"" into table $dbtable FIELDS TERMINATED BY ',' ENCLOSED BY '"\""' LINES TERMINATED BY "\""'\n'"\"" IGNORE 1 LINES"

echo $dbload
# load data local infile "'gfpoint.csv'" into table balabala FIELDS TERMINATED BY ',' ENCLOSED BY '"' LINES TERMINATED BY "''" IGNORE 1 LINES

Answer 5

Make use of $"string".

In this example, it would be,

dbload=$"load data local infile \"'gfpoint.csv'\" into table $dbtable FIELDS TERMINATED BY ',' ENCLOSED BY '\"' LINES TERMINATED BY \"'\n'\" IGNORE 1 LINES"

Note(from the man page):

A double-quoted string preceded by a dollar sign ($"string") will cause the string to be translated according to the current locale. If the current locale is C or POSIX, the dollar sign is ignored. If the string is translated and replaced, the replacement is double-quoted.

Answer 6

Store the double quote character as variable:

dqt='"'
echo "Double quotes ${dqt}X${dqt} inside a double quoted string"

Output:

Double quotes "X" inside a double quoted string