All entries for Monday 04 September 2006

Quotes in Unix Shell and JSTL

Double quote and single quote is different.

Double quote: Everything between quotes is take literally, except for the following characters that keep there special meaning:

• $ variable substitution will occure
• ` command subtitution will occure
• \ escape next character
• ! history character
• newline

Single quote: everything between quotes is take literally, except for the

• ! history
• newline.

For my scripts, it is much safer to use double quote.

One of my script is like this:

/usr/bin/egrep '$2' $1         
if [ $? -eq 0 ] ; then

the single quote surounding $2 caused confusion.

Not so sure about their difference in JSTL. In the “Core JSTL” book, single quote is used.

Hongfeng Sun : 04 Sep 2006 16:47 |  Tags: Unix |  Comments (0) |  Close comments |  Report a problem