pic2tpic: 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/pic2tpic - from package: transfig

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

On Debian possible default full paths are:

/usr/bin/pic2tpic - from package: transfig

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

Error in other languages:
pic2tpic: bevel nie gevind nie
pic2tpic: comandă negăsită
pic2tpic: comando não encontrado
pic2tpic: commande introuvable
pic2tpic: command not found
pic2tpic: käsku ei ole
pic2tpic: không tìm thấy lệnh
pic2tpic: komanda nerasta
pic2tpic: Kommando nicht gefunden.
pic2tpic: kommandot finns inte
pic2tpic: komut yok
pic2tpic: nie znaleziono polecenia
pic2tpic: níor aimsíodh an t-ordú
pic2tpic: no se encontró la orden
pic2tpic: no s'ha trobat l'ordre
pic2tpic: opdracht niet gevonden
pic2tpic: parancs nem található
pic2tpic: perintah tidak ditemukan
pic2tpic: príkaz nenájdený
pic2tpic: příkaz nenalezen
pic2tpic: команда не найдена
pic2tpic: командата не е открита
pic2tpic: 命令找不到
pic2tpic: コマンドが見つかりません