eval: When You Need Another Chance
Ever want to use a variable to get a variable in a shell script or to construct a command on the fly? Find out how in this excerpt from Unix Power Tools, 2nd Edition.
xargs: Problems with Spaces and Newlines
xargs patches up a sticky problem in the original - it choked on filenames with spaces or newlines. Find out how to take advantage of that patch in this excerpt from Unix Power Tools, 2nd Edition.
Using Standard Input and Output
A quick review of basic redirection techniques used by every Unix guru.
Telling tar Which Files to Exclude or Include
Sometimes you don't want to
tar just everything in a directory. Or maybe you want to include some subdirectories and exclude others. Find out how in this excerpt from Unix Power Tools, 2nd Edition.
Protecting Files with the Sticky Bit
Want to keep others from altering or deleting your files even if they have write permissions to your directory? Learn about the sticky bit in this excerpt from Unix Power Tools, 2nd Edition.
Checking Differences with diff
Quickly examine differences between similar files.
Comparing Three Different Versions with diff3
Got three similar files to compare? Use diff3!
Context diffs show the lines around changes in similar files.
ex Scripts Built by diff
diff can build automatic editing scripts you can use to change multiple files or to store a revision history.
Looking for Closure
A gawk script that can be used to make sure items that need to occur in pairs actually do so.
Change Many Files by Editing Just One
Use ed and diff to edit mulitple files.
patch: Generalized Updating of Files that Differ
There's an easy way to make changes based on diffs, use Larry Wall's patch utility.
Handling Command-Line Arguments with a for Loop
Need a shell script that can step through its command line arguments one by one? Read how to do it with a for loop in this excerpt from Unix Power Tools, 2nd Edition.