commandlinefu.com is the place to record those command-line gems that you return to again and again.
Delete that bloated snippets file you've been using and share your personal repository with the world. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.
If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/
You can sign-in using OpenID credentials, or register a traditional username and password.
First-time OpenID users will be automatically assigned a username which can be changed after signing in.
Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.
» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10
Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):
Subscribe to the feed for:
su www-apache/ftp user and then
check readable: find ~/ -type d \( -wholename '/dev/*' -o -wholename '/sys/*' -o -wholename '/proc/*' \) -prune -o -exec test -r {} \; -exec echo {} readable \; 2>/dev/null
check writable: find ~/ -type d \( -wholename '/dev/*' -o -wholename '/sys/*' -o -wholename '/proc/*' \) -prune -o -exec test -w {} \; -exec echo {} writable \; 2>/dev/null
This command is adapted from http://otomaton.wordpress.com/2012/12/26/find-broken-symbolic-links/
Solutions with
find -L
don't work when the link is a loop, an error message is printed.
Applies each file operator using the built-in test.
testt /home/askapache/.sq
/home/askapache/.sq
-a True - file exists.
-d True - file is a directory.
-e True - file exists.
-r True - file is readable by you.
-s True - file exists and is not empty.
-w True - the file is writable by you.
-x True - the file is executable by you.
-O True - the file is effectively owned by you.
-G True - the file is effectively owned by your group.
-N True - the file has been modified since it was last read.
Full Function:
testt ()
{
local dp;
until [ -z "${1:-}" ]; do
dp="$1";
[[ ! -a "$1" ]] && dp="$PWD/$dp";
command ls -w $((${COLUMNS:-80}-20)) -lA --color=tty -d "$dp";
[[ -d "$dp" ]] && find "$dp" -mount -depth -wholename "$dp" -printf '%.5m %10M %#15s %#9u %-9g %#5U %-5G %Am/%Ad/%AY %Cm/%Cd/%CY %Tm/%Td/%TY [%Y] %p\n' -a -quit 2> /dev/null;
for f in a b c d e f g h L k p r s S t u w x O G N;
do
test -$f "$dp" && help test | sed "/-$f F/!d" | sed -e 's#^[\t ]*-\([a-zA-Z]\{1\}\) F[A-Z]*[\t ]* True if#-\1 "'$dp'" #g';
done;
shift;
done
}
Got the idea from there http://fixunix.com/questions/15902-bash-checking-if-env-var-set.html
this avoids several VIM warnings, which I seem too stupid to disable: warning, readonly! and: file and buffer have changed, reload?!
The simplest way to do it.
Works for me, at least. (Why are the variables being set?)
Revised approach to and3k's version, using pipes and read rather than command substitution. This does not require fiddling with IFS when paths have whitespace, and does not risk hitting command-line size limits.
It's less verbose on the missing files, but it stops iterating at the first file that's missing, so it should be definitely faster.
I expanded all the qlist options to be more self-describing.
This loops through all installed ebuilds and checks if every file that should be installed is still there and if not adds it to emerge. It includes a verbose output to stderr too.
If you have packages installed that have whitespace in their filenames you have to change the IFS to "newline".
Oddly, the isatty(3) glibc C call doesn't have a direct analogue as a command 'isatty(1)'. All is not lost as you can use test(1).
For example, your script might be run from a tty or from a GUI menu item but it needs to get user-input or give feedback. Now your script can test STDIN with 'isatty 0' or STDOUT with 'isatty 1' and use xmessage(1) if the tty is not available.
The other way to test for this is with 'tty -s' - but that's only for STDIN.
I often need to know of my directory in the PATH, which one DOES NOT exist. This command answers that question
* This command uses only bash's built-in commands
* The parentheses spawn a new sub shell to prevent the modification of the IFS (input field separator) variable in the current shell
I often use "vim -p" to open in tabs rather than buffers.
I am using .bat commands to execute Curl commands for Twitter API
Locate broken symlinks in the current directory. Also useful, to remove broken links:
find . -type l ! -exec test -e {} \; -print0 | xargs -0 rm