When compiling PHP extensions from source on RHEL 5, you'll typically need these fundamental packages:

• php-devel (contains phpize)
• autoconf (version 2.59 or later)
• automake (version 1.9 or later)
• libtool
• gcc and related build tools

RHEL 5's default repositories are outdated. You'll need to enable EPEL and possibly other repos:

# For 64-bit systems:
wget http://dl.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
rpm -Uvh epel-release-5*.rpm

# For i386 systems:
wget http://dl.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm
rpm -Uvh epel-release-5*.rpm

If repository installations fail, here's how to build from source:

# Install dependencies
yum install gcc make perl-Digest-SHA

# Download and install autoconf
wget http://ftp.gnu.org/gnu/autoconf/autoconf-2.69.tar.gz
tar xzf autoconf-2.69.tar.gz
cd autoconf-2.69
./configure --prefix=/usr/local
make
make install

# Download and install automake
wget http://ftp.gnu.org/gnu/automake/automake-1.15.tar.gz
tar xzf automake-1.15.tar.gz
cd automake-1.15
./configure --prefix=/usr/local
make
make install

With the tools installed, here's how to compile uploadprogress:

# Install PHP development package
yum install php-devel

# Download and prepare the extension
pecl download uploadprogress
tar xzf uploadprogress-*.tgz
cd uploadprogress-*

# Build the extension
phpize
./configure
make
make install

# Enable the extension
echo "extension=uploadprogress.so" > /etc/php.d/uploadprogress.ini
service httpd restart

If you encounter version conflicts:

• Check /usr/local/bin is in your PATH before /usr/bin
• Verify versions with autoconf --version and automake --version
• For PHP version mismatches, ensure php-devel matches your PHP version

For Rackspace Cloud specific issues, their modified kernel might require additional headers:

yum install kernel-devel-$(uname -r)

When working with older RHEL 5 systems (especially in cloud environments like Rackspace), installing development tools can be particularly challenging. The default repositories often lack critical packages needed for PHP extension compilation.

First, let's add the EPEL repository which contains many additional packages:

# As root:
wget https://dl.fedoraproject.org/pub/epel/epel-release-latest-5.noarch.rpm
rpm -Uvh epel-release-latest-5.noarch.rpm

Now install the required development tools:

yum install php-devel automake autoconf libtool gcc make

If packages aren't available through yum, you may need to compile from source. Here's how to build autoconf:

wget http://ftp.gnu.org/gnu/autoconf/autoconf-2.69.tar.gz
tar xzf autoconf-2.69.tar.gz
cd autoconf-2.69
./configure --prefix=/usr/local
make
make install

After installation, verify all components are properly installed:

phpize --version
autoconf --version
automake --version

With dependencies resolved, you can now compile your PHP extension:

pecl install uploadprogress

Or manually:

git clone https://github.com/php/pecl-php-uploadprogress.git
cd pecl-php-uploadprogress
phpize
./configure
make
make install

If you encounter library path issues, try setting these before compilation:

export PHP_PREFIX="/usr"
export PATH=$PHP_PREFIX/bin:$PATH
export PKG_CONFIG_PATH=$PHP_PREFIX/lib/pkgconfig

For complex environments, consider using Docker to avoid dependency issues:

docker run -it centos:5 /bin/bash
# Then follow the same installation steps

Don't forget to add the extension to php.ini:

echo "extension=uploadprogress.so" >> /etc/php.d/uploadprogress.ini
service httpd restart