For disk space constraint testing. Leaves a little space available for creating temp files, etc. Easily free up the used disk space again by deleting the dummy00 file. Can tailor the testing by building smaller 'blocks' to suit the needs of the testing. WARNING: do not do this to the '/' (root) filesystem unless you know what you are doing... on some systems it could crash the OS.

Handled all within awk. Takes the value from $PWD and constructs directory structures and runs commands against them. The gsub() call is not necessary, but added for better visibility. If a variable DIR is given on the awk command-line, then that directory is used instead: awk -vDIR=$HOME/.ssh 'BEGIN{dir=DIR?...}' Show Sample Output

Use the hold space to preserve lines until data is needed.

Useful in while and if statements if not grep string filename; then echo string not found; exit 1; fi

Handles everything except octets with 255. Ran through ip generator with variable octet lengths.

Use of hotcopy for safety/stability of the backups.

Remove everything in current directory except files starting with "ca".

Works in all shells. Does not require a test. Handles like an assertion. Show Sample Output

Searches in order of the directories of $PATH. Stops after finding the entry; looks for only that fileName. Works in Bourne, Korn, Bash and Z shells. Show Sample Output

This can be much faster than downloading one or both trees to a common servers and comparing the files there. After, only those files could be copied down for deeper comparison if needed. Show Sample Output

Removes trailing newline; colon becomes record separator and newline becomes field separator, only the first field is ever printed. Replaces empty entries with $PWD. Also prepend relative directories (like ".") with the current directory ($PWD). Can change PWD with env(1) to get tricky in (non-Bourne) scripts. Show Sample Output

Does not require input to function or complete. Number of iterations controlled by shell variable $NUM. Show Sample Output

Put the positive clauses after the '-o' option.

Manages everything through one sed script instead of pipes of greps and awks. Quoting of shell variables is generally easier within a sed script.

Have wc work on each file then add up the total with awk; get a 43% speed increase on RHEL over using "-exec cat|wc -l" and a 67% increase on my Ubuntu laptop (this is with 10MB of data in 767 files).

Make sure that find does not touch anything other than regular files, and handles non-standard characters in filenames while passing to xargs.

Sends both stdout and stderr to the pipe which captures the data in the file 'out.test' and sends to stdout of tee (likely /dev/tty unless redirected). Works on Bourne, Korn and Bash shells.