UNIX for Dummies Questions & Answers

Hello all. I am going to try my hand at compiling tarballs rather than installing packages.

I have a pretty good understanding of the process and have even compiled/installed Top from source.

But that was an easy install, I want to try something more complex using the various configure flags.

From what I have read, you can specify a number of options with the flags. From my reading, I often see a flag followed by a backslash ("\").

What I am wondering, are there any special rules with regards to the use of these backslashes? IE: single space after the flag and then the backslash? Does the flag denote a return? Is there no backslash used after the last flag in the list?

While on the subject of ./configure, what of the single quotes, are they necessary? I don't see them used too often.

Below is a sample ./configure I got from the MySQL site to demonstrate what I mean:

./configure \
'--prefix=/usr/local/mysql' \
'--disable-dependency-tracking' \
'--enable-assembler' \
'--localstatedir=/usr/local/mysql/data' \
'--libexecdir=/usr/local/mysql/bin' \
'--libdir=/usr/local/mysql/lib' \
'--enable-local-infile' \
'--enable-shared' \
'--enable-thread-safe-client' \
'--with-archive-storage-engine' \
'--with-big-tables' \
'--with-comment=MySQL Community Server (GPL)' \
'--with-extra-charsets=complex' \
'--with-innodb' \
'--with-mysqld-ldflags=-all-static' \
'--with-readline' \
'--with-server-suffix=-standard' \
'--with-unix-socket-path=/tmp/mysql.sock' \
'--with-zlib-dir=bundled' \
'--without-debug' \
'--without-docs' \
'--without-man'

Also why the \ immediately after the ./configure? Rather than say:
./configure --prefix=/usr/local/mysql \
<rest of the text>

is that just to make it neat for the web page and perfectly valid code?

Thank you for your comments.
~Robert

The backslash here has the same meaning as in C: to remove the special meaning from the next character, in this case the newline, making it the same as a regular whitespace. It's used to split a command line into multiple lines for better readability.

And if you want a real challenge AND learn something I'd suggest trying your hand at Linux from Scratch

Pludi:

Thanks for the response, that is a big help. Do you know why the single quotes are being used? I sometimes see them and sometimes not.

As for Linux from scratch....heh, no thanks. I have a hard enough time with Solaris!

~Robert

They aren't really needed in the example, except for the line

Code:

'--with-comment=MySQL Community Server (GPL)'

to tell the shell not to split on the whitespaces but leave them as part of the parameter. It could also be written as

Code:

--with-comment='MySQL Community Server (GPL)'

If I was not using a comment flag, would the single quotes not otherwise been needed?

Probably not, at least not in this example. If you suspect that there's a character that the shell could interpret differently than what you indented, there's almost never harm in adding quotes.

OK, great. Thanks Pludi!