samtools.pl: command not found

Have You tried accessing the binary with the full path?

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/samtools.pl - from package: samtools

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