Join Kevin Skoglund for an in-depth discussion in this video xargs: Passing argument lists to commands, part of Unix for Mac OS X Users.
In this movie we'll learn to use xargs to pass argument lists to commands.…xargs is kind of a funny name.…It's short for execute as arguments.…What xargs does is it parses an input stream into items and then it loops…through each item in that list and passes it to a command.…I think it's easier to understand if we actually see it in action.…So you remember that we had the wc command before for word count.…So if we do word count on our lorem_ipsum.txt file that's inside our Unix files…directory, you see that it comes back and it tells us the number of lines,…words, and characters that are in lorem_ipsum.…
Now, let's try a variation on this.…Let's say if we want to echo lorem_ipsum .txt and we want to pipe that into wc.…Now what it's doing is it's saying not the file lorem_ipsum.txt, but this…string, this actual text lorem_ipsum.txt, how many characters does that have? There is 16.…So that's what it's doing.…It's not looking at the file.…It's looking at the string.…If we instead want to pass that string to wc as an argument, then we use xargs.…
- Moving around the file system
- Creating and reading files
- Copying, moving, renaming, and deleting files and directories
- Creating hard links and symbolic links
- Understanding user identity, file ownership, and sudo
- Setting file permissions with alpha and octal notation
- Changing the PATH variable
- Using the command history
- Directing input and output
- Configuring the Unix working environment
- Searching and replacing using grep and regular expressions
- Manipulating text with tr, sed, and cut
- Integrating with the Finder, Spotlight, and AppleScript
Skill Level Beginner
Q: The exercise files for the following movies appear to be broken:
Is there something wrong with them?
These exercises include one or more "dot files", whose file names start with a period. These files are normally hidden from view by the Finder. So that they would show up in the Finder, the period has been removed from the file names. Additionally, "_example" has been added at the end of the file name to make it clear that the file will not work as-is.
To make the dot files usable, either:
1) Open the file in a text editor to view its contents. Note that it may not be possible to double-click the file to open it because there is no file extension (such as .txt).
2) Resave the file under a new name (usually by choosing File > Save As), adding a "." to the beginning of the file name and removing "_example" from the end.
1) Copy and rename the file from the Unix command line using the techniques discussed in this course. Rename the file by adding a "." to the start and removing "_example" from the end. Include the "-i" option to prevent overwriting an existing file unexpectedly.
Example: cp -i ~/Desktop/Exercise\ Files/Chapter_07/07_02_files/bashrc_example ~/.bashrc
1. Introduction to Unix
2. Filesystem Basics
3. Working with Files and Directories
4. Ownership and Permissions
5. Commands and Programs
6. Directing Input and Output
7. Configuring Your Working Environment
8. Unix Power Tools
9. Useful Mac-Only Commands and Techniques
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