florin.bjdean.id.au - Brad's Notes

Various random notings that I make for future reference...

When piping filenames which include spaces through xargs delimit with null characters instead of newlines:

$ find . -type f -print0 | xargs --null ls -ltrd

A minimal postfix configuration which delivers all email to a local user:

# The alias is still useful for redirecting local users like root
alias_maps = hash:/etc/aliases
# Only allow local connections
inet_interfaces = loopback-only
# Force the delivery transport to be local
default_transport = local
# Redirect any unknown recipient to a local user
luser_relay = my_user

Any email sent via the local postfix will end up either at a local user/alias or at my_user. To be completely safe it would be a good idea to block outgoing SMTP traffic.

To store ALSA sound (including volume) settings between reboots:

sudo alsactl store

apt trusted keys:

  W: GPG error: http://apt-mirror-url distro Release: The following signatures couldn't
  be verified because the public key is not available: NO_PUBKEY XXXXXXXXXXXXXXXX

Grab a key and import:

  $ gpg --keyserver pgp.mit.edu --recv-keys XXXXXXXXXXXXXXXX
  $ gpg --armor --export XXXXXXXXXXXXXXXX | apt-key add -

Setting up the locale for linux after a minimal installation. Often the locale is not generated yet - to do this:

locale-gen $LANG

Further notes in my wiki: Setting Up Locales

Capturing key codes in X Windows - I keep forgetting this so I'm writing it down. The application that helps you out is xev<1):

$ xev
Outer window is 0x4000001, inner window is 0x4000002

KeyRelease event, serial 32, synthetic NO, window 0x4000001,
    root 0x59, subw 0x0, time 379713580, (0,135), root:(296,319),
    state 0x0, keycode 13 (keysym 0x34, 4), same_screen YES,
    XLookupString gives 1 bytes: (34) "4"
    XFilterEvent returns: False

KeyPress event, serial 32, synthetic NO, window 0x4000001,
    root 0x59, subw 0x0, time 379713790, (0,135), root:(296,319),
    state 0x0, keycode 11 (keysym 0x32, 2), same_screen YES,
    XLookupString gives 1 bytes: (32) "2"
    XmbLookupString gives 1 bytes: (32) "2"
    XFilterEvent returns: False

Updating a bunch of music files with useful names but no id3 tags:

$ find . -type f \
    | perl -n -l -e '($n,$t)=m{/0*(\d+)_(.*?)\.mp3};
                     $t =~ tr/_/ /;
                     $t =~ s/(\w+)/\u\L$1/g;
                     `id3 -t "$t" -T "$n" $_`;'

To configure a new virtual interface in Solaris:

  1. To set up virtual interfaces for boot time:
    $ echo "new_hostname" > /etc/hostname.hme0:1
    $ echo "XXX.XXX.XXX.XXX    new_hostname.domain   new_hostname" >> /etc/hosts
  2. To start up the interface without rebooting:
    $ ifconfig hme0:1 plumb
    $ ifconfig hme0:1 XXX.XXX.XXX.XXX up

Dell priority support: 1800 060 889

mod_ssi variable substitution

To use mod_ssi includes of standard headers/footers etc SSI variable substitution can be used, using these commands:

<!--#echo var="varname" encoding="entity" -->
<!--#set var="varname" value="varvalue" -->

<!--#if expr="$varname != ''" -->
<!--#else -->
<!--#endif -->

CVS Repository locking

CVS lock files are on a directory basis so they need to exist in every directory (excluding CVS and Attic directories) to lock an entire repository

<INFO> is an arbitrary string to be appended to the end of each lock filename in for the use of the CVS administrators.

Read Lock:

  1. Create #cvs.lock directory
  2. Create #cvs.rfl.<INFO> file
  3. Remove #cvs.lock directory
  4. Read
  5. Remove #cvs.rfl.<INFO> file

Write Lock:

  1. Create #cvs.lock directory
  2. Check for #cvs.rfl.* (abort if there)
  3. Create #cvs.wfl.<INFO> file
  4. Write to repository
  5. Remove #cvs.wfl.<INFO> file
  6. Remoe #cvs.lock directory

To avoid deadlock:

remove all locks on failure to attain full lock

For Backup:

Use a Read Lock

grif processing embedded eps files - a note about photoshop

Just so you know (in case this happens to someone else who uses photoshop). I used the default eps settings. I turned off TIFF preview and "Include halftone" screen, and it all works fine (abiet very low quality, but hey it works!).

openssl certificate handling...

To convert a PEM certificate to DER (p12):
openssl pkcs12 -export -in <pemfile> -out <derfile>
To convert a DER (p12) certificate to PEM:
Note: The PEM file created includes the private key, then the CA public cert and finally the public cert.
openssl pkcs12 -nodes -in <derfile> -out <pemfile>
To generate a private key (1024bit, DES encrypted):
openssl genrsa -out private.key -des 1024
To generate a self-signed certificate (given an existing private key):
openssl req -new -x509 -key <path-to-private-key> -out self-signed.pem -days 3650
Createing the hash symlink to a certificate (e.g. in /etc/ssl/certs):
ln -s some-cert.pem `openssl x509 -noout -hash -in some-cert.pem`.0

(Tue Dec 20 11:13:27 EST 2016) I wrote those notes a while back, these days for HTTPS support life is very easy thanks to LetsEncrypt and the certbot utility.

A handy a2ps printing line...

a2ps --delegate=no --pretty-print=html --columns=1 --landscape --chars-per-line=160 filename

FrameMaker core dumping when running to linux - solution from CERN

On some Linux machines, FrameMaker is opening the license window and core
dumping: FM is only running on 8 bpp on your screen but your configuration may
be 16 or more. Here is a solution you can try on your Linux desktop: 

1. Create a ~/.xinitrc file containing: 

# Sample ~/.xsession file

export PATH
ksh /usr/local/lib/hepix/X11/site/xclients&
$FVWM2 -f ~/.hepix/wm/generated_fvwm2rc

2. Make it executable: chmod +x ~/.xinitrc 
3. Launch a new graphic environment with 8 bpp: startx -bpp 8 -- :1 
4. Check your environment and start FrameMaker 

If it does not work properly, contact linux.support, attach this page and ask
them to modify the X server configuration so that 8, 16 and maybe more bpp are
available at the same time.

Note that this is also solved by setting the depth to 24 so it's just 16 that seems to be problem...

Framemaker license allocation failing - use fmflsadm

"fmflsadm ping" checks if the license server is running

"fmflsadm verify" checks the running license server and will clear any stale/expired license allocations

"fmflsadm -help" for help...

Common substituion in multiple files... (bash)

for x in files ; do sed -e 'blah' $x > $$ ; mv $$ $x ; done

... or better:

perl -p -i -e 's/foo/bar/g;' files