idevicesyslog: 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/idevicesyslog - from package: libimobiledevice

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

On Debian possible default full paths are:

/usr/bin/idevicesyslog - from package: libimobiledevice-utils

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

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