Commands by TeacherTiger

Commands by TeacherTiger (5)

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Save the current directory without leaving it

Save the current directory without having to leave it. When you do decide to leave the current directory, use popd to return to it.
This is sample output - yours may be different.
1

pushd .

TeacherTiger · 2010-11-27 23:21:37 5
watch the previous command

If you just executed some long command, like "ps -aefww | grep -i [m]yProcess", and if you don't want to retype it or cycle backwards in history and waste time quoting it, then you can use history substitution.
This is sample output - yours may be different.
1

watch -n1 -d !!

TeacherTiger · 2009-11-24 21:01:14 4
List all symbolic links in current directory

For those who don't have the symlinks command, you can use readlink. This command is not straightforward because readlink is very picky. The backslash in front of 'ls' means not to use an alias (e.g. color escape codes from an aliased 'ls' could mess up readlink), and the -1 (one) means to print the entries separated by newlines. xargs -l (the letter L) means to process each input separated by newlines as separate commands.
This is sample output - yours may be different.
2

\ls -1 | xargs -l readlink

TeacherTiger · 2009-11-23 19:28:03 8
remove files and directories with acces time older than a given time

Deletes files older than "n" minutes ago. Note the plus sign before the n is important and means "greater than n". This is more precise than atime, since atime is specified in units of days. NOTE that you can use amin/atime, mmin/mtime, and cmin/ctime for access, modification, and change times, respectively. Also, using -delete is faster than piping to xargs, since no piping is needed.
This is sample output - yours may be different.
-1

find -amin +[n] -delete

TeacherTiger · 2009-11-20 17:15:28 5
Print stack trace of a core file without needing to enter gdb interactively

The pstack command prints a stack trace of running processes without needing to attach a debugger, but what about core files? The answer, of course, is to use this command. Usage: gdbbt program corefile
This is sample output - yours may be different.
3

alias gdbbt="gdb -q -n -ex bt -batch"

TeacherTiger · 2009-11-10 22:56:59 746

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Use default value if unassigned

Will use variable value (for variable $my_dir, in this case), an assign a default value if there is none.

Quick directory bookmarks

Set a bookmark as normal shell variable $ p=/cumbersome/path/to/project To go there $ to p This saves one "$" and is faster to type ;-) The variable is still useful as such: $ vim $p/ will expand the variable (at least in bash) and show a list of files to edit. If setting the bookmarks is too much typing you could add another function $ bm() { eval $1=$(pwd); } then bookmark the current directory with $ bm p

Create a bunch of dummy files for testing

Sometimes I need to create a directory of files to operate on to test out some commandlinefu I am cooking up. The main thing is the range ({1..N}) expansion.

Convert CSV to JSON

Replace 'csv_file.csv' with your filename.

list block devices

Shows all block devices in a tree with descruptions of what they are.

Lookup autonomous systems of all outgoing http/s traffic

List alive hosts in specific subnet

Works on any machine with nmap installed. Previous version does not work on machines without "seq". Also works on subnets of any size.

Convert CSV to JSON

Replace 'csv_file.csv' with your filename.

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