strings: 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/strings - from package: binutils

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

On Debian possible default full paths are:

/usr/bin/strings - from package: binutils-multiarch
/usr/bin/strings - from package: binutils
/usr/lib/plan9/bin/strings - from package: 9base

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

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