Category: Code

bash redirect output STDOUT STDERR

HOWTO redirect output: STDOUT / STDERR

Examples:

output or stdout to screen
$ echo "test"

redirects stdout to afile.txt
$ echo "test" > afile.txt

  • 0 is stdin.
  • 1 is stdout.
  • 2 is stderr.

also redirects stdout to afile.txt
$ echo "test" 1> afile.txt

redirect stderr to afile.txt
$ echo "test" 2> afile.txt

>& is the syntax to redirect a stream to another file descriptor

redirect stdin to stderr
$ echo "test" 1>&2
# or
$ echo "test" >&2

..or vice versa:

$ echo "test" 2>&1

So, in short.. 2> redirects STDERR to an (unspecified) file, appending &1 redirects STDERR to STDOUT

PHP5 session_start failed, opendir permission denied.

Today i got the PHP Error:
“session_start() [function.session-start]: ps_files_cleanup_dir: opendir(/var/lib/php5) failed: Permission denied (13) in …”.

reproduce bug:


ini_set('session.gc_probability',1000);
ini_set('session.gc_divisor',1000);

Continue reading “PHP5 session_start failed, opendir permission denied.”

dpkg conflict libmagic1 /etc/magic.mime


Preconfiguring packages ...
(Reading database ... 131336 files and directories currently installed.)
Preparing to replace libmagic1 4.26-1 (using .../libmagic1_5.04-5_i386.deb) ...
Unpacking replacement libmagic1 ...
dpkg: error processing /var/cache/apt/archives/libmagic1_5.04-5_i386.deb (--unpack):
trying to overwrite '/etc/magic.mime', which is also in package file 5.04-5
Selecting previously deselected package libdb4.8.
Unpacking libdb4.8 (from .../libdb4.8_4.8.30-2_i386.deb) ...
Processing triggers for man-db ...
Errors were encountered while processing:
/var/cache/apt/archives/libmagic1_5.04-5_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

this is a debian squeeze problem, you can fix this by:

  1. (re)moving /etc/magic.mime
  2. install the libmagic package manually with force options

dpkg --force-overwrite -i /var/cache/apt/archives/libmagic1_5.04-5_i386.deb