This will display only lines 40-50 in a file called lines.txt.
$ cat lines.txt | head -n 50 | tail -n 10 |
For lines 90-100.
$ cat lines.txt | head -n 100 | tail -n 10 |
and so on.
display
Memory Info on Linux
Here’s how to view system memory on Linux.
Default display is in kB
cat /proc/meminfo MemTotal: 7492768 kB MemFree: 427368 kB MemAvailable: 5424768 kB |
Display in MB
awk '$3=="kB"{$2=$2/1024;$3="MB"} 1' /proc/meminfo | column -t MemTotal: 7317.16 MB MemFree: 404.527 MB MemAvailable: 5285.4 MB |
Output in GB
awk '$3=="kB"{$2=$2/1024^2;$3="GB";} 1' /proc/meminfo | column -t MemTotal: 7.14566 GB MemFree: 0.370392 GB MemAvailable: 5.13733 GB |
Linux prompt display current directory only
Here’s the command to display only the current directory.
export PROMPT_DIRTRIM=1 |
Place the command in your ~/.bashrc to make it permanent.
GCP Display Roles on Service Account
How to display roles assigned to a GCP service account.
gcloud projects get-iam-policy your-project-id \ --flatten="bindings[].members" \ --format='table(bindings.role)' \ --filter="bindings.members:your-service-account@your-project.iam.gserviceaccount.com" |
Result
ROLE organizations/xxxxxxxxxxxxx/roles/role-name roles/compute.instanceAdmin.v1 roles/compute.networkViewer roles/logging.logWriter roles/monitoring.metricWriter |
GCP Display Device Names on OS
In GCP console you can see the VM’s Device Names. In this case, it’s boot and persistent-disk-1.
Name Device name
server-boot boot
server-data persistent-disk-1 |
To display the volume names on the OS, run this command.
$ ls -l /dev/disk/by-id total 0 lrwxrwxrwx. 1 root root 9 Aug 2 01:12 google-boot -> ../../sda lrwxrwxrwx. 1 root root 10 Aug 2 01:12 google-boot-part1 -> ../../sda1 lrwxrwxrwx. 1 root root 9 Aug 18 18:48 google-persistent-disk-1 -> ../../sdb lrwxrwxrwx. 1 root root 9 Aug 2 01:12 scsi-0Google_PersistentDisk_boot -> ../../sda lrwxrwxrwx. 1 root root 10 Aug 2 01:12 scsi-0Google_PersistentDisk_boot-part1 -> ../../sda1 lrwxrwxrwx. 1 root root 9 Aug 18 18:48 scsi-0Google_PersistentDisk_persistent-disk-1 -> ../../sdb |
As you can see, boot and persistent-disk-1 are displayed along with its device names /dev/sda and /dev/sdb.
Display Sequential Write Throughput
Here’s a dd command to display sequential write throughput from the command line.
time dd if=/dev/zero of=/mounted_backup_volume/zero.raw bs=1M count=512 status=progress |
Output is.
512+0 records in 512+0 records out 536870912 bytes (537 MB) copied, 0.667813 s, 804 MB/s real 0m0.669s user 0m0.000s sys 0m0.359s |
Windows Route Add
Here’s how to add a route in Windows. Open CMD as Administrator.
route add 10.10.10.10 mask 255.255.255.0 10.10.10.254 |
To make it persistent, add -p.
route add 10.10.10.10 mask 255.255.255.0 10.10.10.254 |
To display. Specifies IP 4 only.
route print -4 |
Windows + Tab
Found another gem to display all Windows by using …
Windows + Tab |