gajim-history-manager: 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/gajim-history-manager - from package: gajim

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

On Debian possible default full paths are:

/usr/bin/gajim-history-manager - from package: gajim

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

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