gflags_completions.sh: 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/gflags_completions.sh - from package: gflags

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

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