pecl: 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/pecl - from package: php54w-pear
/usr/bin/pecl - from package: php55w-pear
/usr/bin/pecl - from package: php56w-pear
/usr/bin/pecl - from package: php70w-pear
/usr/bin/pecl - from package: php-pear

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

On Debian possible default full paths are:

/usr/bin/pecl - from package: php-pear

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

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