To learn more about umask, read Alex Juarez’s article covering umask and permissions in general. These new files are subject to your default umask settings. Using cat to read the contents of a file into another file, however, invokes a system call to create a new file. That means that the file permissions of the duplicate are the same as the original: $ ls -l -G -g When you use cp to copy a file, the file’s attributes are copied along with the file itself. The significance of using cat to copy a file is the way the system interprets the action. For instance, with cat you can create two copies from one file with just a single command. Among everything else cat does (including its intended purpose of con catenating files), it can also copy. The cat command is one of the most misunderstood commands, but only because it exemplifies the extreme flexibility of a POSIX system. Without the -r option, cp doesn’t even recognize a directory as an object that can be copied: $ cp notes/ notes-backupĬp: -r not specified omitting directory 'notes/' This option runs cp on the directory inode, and then on all files within the directory. To copy a directory, you must use the -r option, which stands for - recursive. That fact is important because it allows you to make a copy of a file in the same directory as the original: $ cp example.txt example.txtĬp: 'example.txt' and 'example.txt' are the same file. You can also, conveniently (and efficiently), rename the file as you copy it: $ cp example.txt ~/Documents/example_copy.txt Instead, cp detects that Documents is a folder, and places a copy of example.txt into it. Just like when you drag and drop a file onto a folder, this action doesn’t replace Documents with example.txt. It uses the familiar source and target (strictly in that order) syntax, so to copy a file called example.txt into your Documents directory: $ cp example.txt ~/Documents This command copies files and directories and is relatively straightforward. The obvious terminal-based equivalent to copying and pasting a file on the desktop is the cp command. While the GUI is a generally familiar way to copy files, copying in a terminal can be more efficient. When you paste, your file manager looks at the path in your clipboard and then runs a copy command, copying the file located at that path to the path you are pasting into. In this case, you’re not actually copying the file’s contents to your clipboard.
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