gif2h5: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/lib64/mpich/bin/gif2h5 - from package: hdf5-mpich
/usr/lib/mpich/bin/gif2h5 - from package: hdf5-mpich
/usr/lib64/openmpi/bin/gif2h5 - from package: hdf5-openmpi
/usr/lib/openmpi/bin/gif2h5 - from package: hdf5-openmpi
/usr/bin/gif2h5 - from package: hdf5

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/gif2h5 - from package: hdf5-tools

You may install the required package with command apt-get install {package}

Error in other languages:
gif2h5: bevel nie gevind nie
gif2h5: comandă negăsită
gif2h5: comando não encontrado
gif2h5: commande introuvable
gif2h5: command not found
gif2h5: käsku ei ole
gif2h5: không tìm thấy lệnh
gif2h5: komanda nerasta
gif2h5: Kommando nicht gefunden.
gif2h5: kommandot finns inte
gif2h5: komut yok
gif2h5: nie znaleziono polecenia
gif2h5: níor aimsíodh an t-ordú
gif2h5: no se encontró la orden
gif2h5: no s'ha trobat l'ordre
gif2h5: opdracht niet gevonden
gif2h5: parancs nem található
gif2h5: perintah tidak ditemukan
gif2h5: príkaz nenájdený
gif2h5: příkaz nenalezen
gif2h5: команда не найдена
gif2h5: командата не е открита
gif2h5: 命令找不到
gif2h5: コマンドが見つかりません