Commands by totoro (6)

  • If you enable multiuser, then you can permit others to share your screen session. The following conditions apply: 1. screen must be suid root; 2. "multiuser on" must be configured in ~/.screenrc; 3. control the others user(s) access with "aclchg": # ----- from ~/.screenrc-users ----- aclchg someuser +rx "#?" #enable r/o access to "someuser" aclchg someuser -x "#,at,aclchg,acladd,acldel,quit" # don't allow these aclchg otheruser +rwx "#?" # enable r/w access to "otheruser" aclchg otheruser -x "#,at,aclchg,acladd,acldel,quit" # don't allow them to use these commands # ----- After doing this (once), you start your session with: $ screen Then, the other user can join your terminal session(s) with youruserid: $ screen -r youruserid/ Note: the trailing "/" is required. Multiple users can share the same screen simultaneously, each with independent access controlled precisely with "aclchg" in the ~/.screenrc file. I use the following setup: # ~/.screenrc-base # default screenrc on any host source $HOME/.screenrc-base source $HOME/.screenrc-$HOST source $HOME/.screenrc-users # ----- Then, the base configurations are in ~/.screenrc-base; the host-specific configurations are in ~/.screenrc-$HOST, and the user configurations are in ~/.screenrc-users. The host-specific .screenrc file might contain some host-specific screen commands; e.g.: # ~/.screen-myhost # ----- screen -t 'anywhere' /bin/tcsh screen -t 'anywhere1' /bin/tcsh # ---- The .screenrc-base contains: # ~/.screenrc-base ## I find typing ^a (Control-a) awkward. So I set the escape key to CTRL-j instead of a. escape ^Jj termcapinfo xterm* ti@:te@: autodetach on zombie kr verbose on multiuser on


    38
    % screen -r someuser/
    totoro · 2009-03-25 23:59:38 12
  • If you have lots of remote hosts sitting "behind" an ssh proxy host, then there is a special-case use of "rsynch" that allows one to easily copy directories and files across the ssh proxy host, without having to do two explicit copies: the '-e' option allows for a replacement "rsh" command. We use this option to specify an "ssh" tunnel command, with the '-A' option that causes authentication agent requests to be forwarded back to the local host. If you have ssh set up correctly, the above command can be done without any passwords being entered.


    5
    rsync -avz -e 'ssh -A sshproxy ssh' srcdir remhost:dest/path/
    totoro · 2009-03-25 21:29:07 11
  • Many Mac OS X programs, especially those in Microsoft:Office, create ASCII files with lines terminated by CRs (carriage returns). Most Unix programs expect lines separated by NLs (newlines). This little command makes it trivial to convert them. Show Sample Output


    -2
    function crtonl { perl -i -ape 's/\r\n?/\n/g;' $* ; }
    totoro · 2009-03-25 20:28:32 10
  • This little command (function) shows the CSV header fields (which are field names separated by commas) as an ordered list, clearly showing the fields and their order. Show Sample Output


    0
    function headers { head -1 $* | tr ',' '\12' | pr -t -n ; }
    totoro · 2009-03-25 20:07:47 14
  • Coming back to a project directory after sometime elsewhere? Need to know what the most recently modified files are? This little function "t" is one of my most frequent commands. I have a tcsh alias for it also: alias t 'ls -ltch \!* | head -20' Show Sample Output


    0
    function t { ls -ltch $* | head -20 ; }
    totoro · 2009-03-25 20:05:52 8
  • Ever wanted to find the most recently modified files, but couldn't remember exactly where they were in a project directory with many subdirectories? The "find" command, using a combination of "-mtime -N" and "-depth -D" can be used to find those files. If your directory structure isn't very deep, just omit the "-depth -D", but if your directory structure is very deep, then you can limit the depth of the traversal using "-depth -D", where "D" is the maximum number of directory levels to descend. Show Sample Output


    -2
    find . -type f -depth -3 -mtime -5
    totoro · 2009-03-25 19:54:06 5

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display a smiling smiley if the command succeeded and a sad smiley if the command failed
you could save the code between if and fi to a shell script named smiley.sh with the first argument as and then do a smiley.sh to see if the command succeeded. a bit needless but who cares ;)

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Exiftool adjust Date & Time of pictures
Change the original date set by camera : Create Date : 2020:08:21 13:26:24.63 //Operating System: Date Created (ie: sdcard) Date/Time Original : 2020:08:21 13:26:24.63 // Set by camrea when you point and click for photo Modify Date : 2020:08:21 13:26:24.63 //Operating System: Modified (ie: sdcard) Exif argument examples are : exiftool.exe ā€œ-DateTimeOriginal+=0:0:0 5:30:0ā€ filename.jpg (add 5 hours and 30 minutes to the Exif Date/Time Original) exiftool.exe" "-modifydate-=0:0:0 0:25:0" filename.jpg (reduce the Exif Modify Date to 25 minutes) exiftool.exe ā€œ-AllDates+=Y:M:D h:m:sā€ filename.jpg (Change all exif date values to Y:M:D h:m:s)

Show UDID of iPhone
Display the serial of the iPhone (aka UDID).

encrypt and post or get and decrypt from sprunge using gpg symmetric encryption option
create simple encrypted notes to yourself using a passphrase on sprunge.us

seq (argc=2) for FreeBSD

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Find an installed app


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