Updating Curl

Is there any bad side effects if i update myself to latest version of curl?

Anything from no problems to operational chaos. I'd tend to assume the lower end of that range, but then if you mess up your PATH, or overwrite system pieces, or if there's a bug or a rogue deletion, well, all bets are off.

Make a backup before you might potentially corrupt your environment.

You will now own debug, integration, troubleshooting and upgrades, and you also own knowing how to back this stuff out if/when you want or need to revert to the system-installed version of cURL.

What is the difference between these two?
curl+ssl-7.21.4-1-osx5-x86.tar.gz
curl+ssl-7.21.4-1-osx6-x86.tar.gz

Likely built for 10.5 and for 10.6, respectively.

Is there any bad side effects if i update myself to latest version of curl?

What is the difference between these two?
curl+ssl-7.21.4-1-osx5-x86.tar.gz
curl+ssl-7.21.4-1-osx6-x86.tar.gz

Is there new functionality you need in curl+ssl-7.21.4-1-osx6-x86.tar.gz? Looking at the version information 7.21.4-1, they both look like the same version. If that is the case, what advantage do you expect to get?

If there is some new functionality in curl+ssl-7.21.4-1-osx6-x86.tar.gz, then you would be smart NOT to replace /usr/bin/curl, but rather install it and any related components at /usr/local/bin/curl, and then arrange your PATH so that your Terminal sessions use your curl, but any Mac OS X dependent usage will use the version that was shipped with the OS, and thus not break anything.

Also putting your copy i /usr/local/bin means that if a Mac OS X update comes along and replaces /usr/bin/curl, it will not affect your personal copy.

Of course if in 2 or 3 years, Mac OS X updated /usr/bin/curl to an even newer version, but your PATH still points to /usr/local/bin/curl and you have not updated it, then you might wonder why you are not getting the new features that the Mac OS X man page for curl says should be there 🙂

Trying to be our own system integrator is so much fun 🙂

So how i can force install it here? /usr/local/bin/curl

You need to read the makefile and see what it implements here.

How i can check do i have all these?

Dependencies:
c-ares 1.7.4
g95 20090624
gawk 3.1.8
gettext 0.18.1.1
libiconv 1.13.1
perl 5.12.2
sed 4.2.1
texinfo 4.13

By looking for the default location and in any locally-installed version in your path, and then using the package-specific mechanism of determining the version. c-ares and g95 are not part of Mac OS X, so you'll have to add those. I didn't check further.

Where are you getting this package from? Curl doesn't need FORTRAN!

http://curl.haxx.se/docs/libs.html

Though you may well have considered it, could you provide some details around this statement:

I have some problems with curl and thats why i try to update.

This before jumping into the very deep end of customized and advanced Mac system management.

What's broken? What happened? Diagnostics? Maybe there's a workaround here?

That makefile is total gibberish to me

That's what is getting installed and what you will be responsible for maintaining and upgrading and troubleshooting (or convincing somebody else to maintain this for you), so do you really need to go down this path?

Can you explain what you need from the 7.21.4 version that 7.12.1 doesn't provide?

If the makefile is gibberish, I strongly suggest getting a binary release.