complete-ant-cmd.pl: 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/complete-ant-cmd.pl - from package: ant-scripts
/usr/lib64/eclipse/plugins/org.apache.ant_1.7.1.v20100518-1145/bin/complete-ant-cmd.pl - from package: eclipse-platform

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

On Debian possible default full paths are:

/usr/share/ant/bin/complete-ant-cmd.pl - from package: ant
/usr/lib/eclipse/plugins/org.apache.ant_1.8.3.v20120321-1730/bin/complete-ant-cmd.pl - from package: eclipse-platform-data

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

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