[Libguestfs] [PATCH] appliance: use bash features for string matching in files
Richard W.M. Jones
rjones at redhat.com
Tue Mar 22 18:59:01 UTC 2016
On Tue, Mar 22, 2016 at 03:48:53PM +0100, Pino Toscano wrote:
> Read the content of /proc/cmdline using bash features, and use its
> [[ ... ]] expression to find texts in a variable.
>
> This shaves off 5 grep invocations.
> ---
> appliance/init | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/appliance/init b/appliance/init
> index f6fe9b9..8d662fa 100755
> --- a/appliance/init
> +++ b/appliance/init
> @@ -75,7 +75,9 @@ $UDEVD --daemon #--debug
> udevadm trigger
> udevadm settle --timeout=600
>
> -if grep -sq selinux=1 /proc/cmdline; then
> +cmdline=$(</proc/cmdline)
> +
> +if [[ $cmdline == *selinux=1* ]]; then
> mount -t selinuxfs none /sys/fs/selinux
> fi
>
> @@ -91,16 +93,16 @@ shopt -u nullglob
> hwclock -u -s
>
> # Parse the kernel command line.
> -if grep -sq guestfs_verbose=1 /proc/cmdline; then
> +if [[ $cmdline == *guestfs_verbose=1* ]]; then
> guestfs_verbose=1
> fi
> -if grep -sq guestfs_network=1 /proc/cmdline; then
> +if [[ $cmdline == *guestfs_network=1* ]]; then
> guestfs_network=1
> fi
> -if grep -sq guestfs_rescue=1 /proc/cmdline; then
> +if [[ $cmdline == *guestfs_rescue=1* ]]; then
> guestfs_rescue=1
> fi
> -if grep -sq guestfs_noreboot=1 /proc/cmdline; then
> +if [[ $cmdline == *guestfs_noreboot=1* ]]; then
> guestfs_noreboot=1
> fi
> eval `grep -Eo 'guestfs_channel=[^[:space:]]+' /proc/cmdline`
ACK.
Rich.
--
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