Linux Ask! is a Q & A web site specific for Linux related questions. Questions are collected, answered and audited by experienced Linux users.
Post a file to a server using the Curl command
Answer:
You can simulate a HTTP form post, with a file being uploaded to a remote server using the curl command.
curl -F 'photo=@/upload/image.jpg' http://example.com/upload.phpAssume the name of the form element of your upload is called "photo"
Create a transparent image using ImageMagick
Answer:
You can use the following command to create an empty png file, using the ImageMagick.
# convert -size 100x100 xc:none empty.png
an empty png of size 100x100 will be created.
Edit a remote file with vim over SSH
Answer:
If you have a remote file and you can have a quick edit, if you use the following command:
# ssh -t john@remote-server vim /data/test.txt
You will be prompted to login if you don't have proper ssh key in the remote server, and after finishing editing the file, you will quit the ssh session automatically.
Sort numerical value using the sort command
Answer:
Assume you have a text file contains the following content:
1
2
3
10When you use the sort command to sort them, it will give the following output:
# sort test.txt
1
10
2
3So you need to sort them according to the numerical values?
Try with the n flag:
# sort -n test.txt
1
2
3
10Revert uncommitted change in Git
Answer:
To revert the changes of a uncommitted file in Git, you need to use the following command:
# git checkout file
