lsdiff: 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/lsdiff - from package: patchutils

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

On Debian possible default full paths are:

/usr/bin/lsdiff - from package: patchutils

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

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