How to install m4




I want to install ffmpeg-php extension, but for that I need autoconf. So I’ve tried to install autoconf, but when I type ./configure this error is showed:

checking for a BSD-compatible install… /usr/bin/install -c
checking whether build environment is sane… yes
checking for a thread-safe mkdir -p… /bin/mkdir -p
checking for gawk… gawk
checking whether make sets $(MAKE)… yes
checking whether /bin/sh -n is known to work… yes
checking for expr… /usr/bin/expr
checking for GNU M4 that supports accurate traces… configure: error: no acceptable m4 could be found in $PATH.
GNU M4 1.4.5 or later is required; 1.4.11 is recommended

So, could somebody help me?