ltrace: 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/ltrace - from package: ltrace

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

On Debian possible default full paths are:

/usr/bin/ltrace - from package: ltrace

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

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