Bash: Read a file into a variable
value=$(<config.txt)
value is the variable to which you want to read the file into.
Replace config.txt with the file you want to be read.
GNU/Linux
Pull all Git repositories you have access to
ssh [email protected] info | cut -f 2 | tail -n +3 | xargs -I {} -n 1 -I_repository -- sh -c 'cd _repository; git pull; cd ..;'
The above command will connect to the git server (git.bytefreaks.net) using gitolite and get a list of all the repositories you have access to using ssh [email protected] info
The command should return a list similar to this:
hello bytefreaks, this is git@git running gitolite3 v3.5.3.1-1-gf8776f5 on git 1.7.1 R W Repo1 R W Repo2 R W Repo3 R Repo4
From the results, we remove the first 3 lines as they contain no useful information to cloning all the repositories. From the rest of the lines, where each line contains the information for a repository we have access to, we keep the third column only as it is the one that holds the repository name as it is stored on the server.
Afterwards it will remove all columns except the second to filter the column with the repository names and will remove the first 3 lines to keep only the data we are interested in.
On the last stage of the pipe we have a list of the names of the repositories, using xargs, we assign each repository name to the _repository variable and using one result at a time, we navigate into the folder of the repository using cd and call the pull command.
Note: We assume that all repositories are in the current folder as children and each one is in a sub-folder of its own which is named as the repository is.
Clone all repositories you have access to over ssh
ssh [email protected] info | cut -f 2 | tail -n +3 | xargs -I {} -n 1 git clone ssh://[email protected]/{}
The above command will connect to the git server (git.bytefreaks.net) that is using gitolite and get a list of all the repositories you have access to using ssh [email protected] info
The command should return a list similar to this:
hello bytefreaks, this is git@git running gitolite3 v3.5.3.1-1-gf8776f5 on git 1.7.1 R W Repo1 R W Repo2 R W Repo3 R Repo4
From the results, we remove the first 3 lines as they contain no useful information to cloning all the repositories. From the rest of the lines, where each line contains the information for a repository we have access to, we keep the third column only as it is the one that holds the repository name as it is stored on the server.
On the last stage of the pipe we have a list of the names of the repositories, using xargs, we assign each repository name to the special variable {} and processing one result at a time we clone the git repository to the current directory under the folder that is named as the repository.
ffmpeg: Extract audio from .WEBM to .OGG 3
If you need to extract the audio from an .WEBM movie file to an .OGG audio file you can execute the following:
FILE="the-file-you-want-to-process.webm";
ffmpeg -i "${FILE}" -vn -y "${FILE%.webm}.ogg"
The first command will assign the file name to a variable, we do this to avoid typing errors in the second command where we might want to use the same name for the audio file.
The second command, will use ffmpeg to extract the audio. The -i flag, indicates the file name of the input. We used the flag -vn that will instruct ffmpeg to disable video recording. The -acodec flag will set the output audio codec to vorbis. The -y flag will overwrite output file without asking, so be careful when you use it.
In case we want to automatically process (batch process) all .WEBM video files in a folder we can use the following:
for FILE in *.webm;
do
echo -e "Processing video '\e[32m$FILE\e[0m'";
ffmpeg -i "${FILE}" -vn -y "${FILE%.webm}.ogg"
done
The above script will find all .WEBM files in the folder and process them one after the other.
UPDATE:
The following command will find all webm files that are in the current directory and in all sub-folders and extract the audio to ogg format.
find . -type f -iname "*.webm" -exec bash -c 'FILE="$1"; ffmpeg -i "${FILE}" -vn -y "${FILE%.webm}.ogg";' _ '{}' \;
The filename of the audio file will be the same as the webm video with the correct extension. The webm extension will be removed and replaced by the ogg extension e.g hi.webm will become hi.ogg
