// To create the .po (write your translations to this file):
$ find *.php ../includes/* ../modules/*.module ../misc/*.php ../theme/* | xargs xgettext -L PHP -o ari.po --keyword=_ -

// To create the utf-8 .po  
$ iconv -f iso-8859-1 -t utf-8 -o ari.utf-8.po ari.po

// To create the .mo:  
$ msgfmt -v ari.utf-8.po -o ari.mo

// To update (assume both files to be merged are utf-8)
$ msgmerge es_ES/LC_MESSAGES/ari.po ari.utf-8.po --output-file=es_ES/LC_MESSAGES/ari.po
$ msgfmt -v es_ES/LC_MESSAGES/ari.po -o es_ES/LC_MESSAGES/ari.mo


// script
//   for this to work all translated files need to be converted to utf-8 (use iconv)
//
find *.php ../includes/* ../modules/*.module ../misc/*.php ../theme/* | xargs xgettext -L PHP -o ari.po --keyword=_ -
iconv -f iso-8859-1 -t utf-8 -o ari.utf-8.po ari.po
msgmerge el_GR/LC_MESSAGES/ari.po ari.utf-8.po --output-file=el_GR/LC_MESSAGES/ari.po
msgfmt -v el_GR/LC_MESSAGES/ari.po -o el_GR/LC_MESSAGES/ari.mo
msgmerge es_ES/LC_MESSAGES/ari.po ari.utf-8.po --output-file=es_ES/LC_MESSAGES/ari.po
msgfmt -v es_ES/LC_MESSAGES/ari.po -o es_ES/LC_MESSAGES/ari.mo
msgmerge fr_FR/LC_MESSAGES/ari.po ari.utf-8.po --output-file=fr_FR/LC_MESSAGES/ari.po
msgfmt -v fr_FR/LC_MESSAGES/ari.po -o fr_FR/LC_MESSAGES/ari.mo
msgmerge he_IL/LC_MESSAGES/ari.po ari.utf-8.po --output-file=he_IL/LC_MESSAGES/ari.po
msgfmt -v he_IL/LC_MESSAGES/ari.po -o he_IL/LC_MESSAGES/ari.mo
msgmerge hu_HU/LC_MESSAGES/ari.po ari.utf-8.po --output-file=hu_HU/LC_MESSAGES/ari.po
msgfmt -v hu_HU/LC_MESSAGES/ari.po -o hu_HU/LC_MESSAGES/ari.mo
msgmerge it_IT/LC_MESSAGES/ari.po ari.utf-8.po --output-file=it_IT/LC_MESSAGES/ari.po
msgfmt -v ot_IT/LC_MESSAGES/ari.po -o it_IT/LC_MESSAGES/ari.mo
msgmerge pt_BR/LC_MESSAGES/ari.po ari.utf-8.po --output-file=pt_BR/LC_MESSAGES/ari.po
msgfmt -v pt_BR/LC_MESSAGES/ari.po -o pt_BR/LC_MESSAGES/ari.mo
msgmerge sv_SE/LC_MESSAGES/ari.po ari.utf-8.po --output-file=sv_SE/LC_MESSAGES/ari.po
msgfmt -v sv_SE/LC_MESSAGES/ari.po -o sv_SE/LC_MESSAGES/ari.mo