pbmlife: 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/bin/pbmlife - from package: netpbm-progs

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

On Debian possible default full paths are:

/usr/bin/pbmlife - from package: netpbm

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

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