what is the operative readlink command?

[jpvrlaone]

I stumlbed accross a problem where a script kept failing when running the readlink command.
It did not like the use of the -f flag which is supported in the man page. I got past the problem using /usr/lib/klibc/bin/readlink found through a search of the system. More details can be found in the forum using the tag "readlink".
What is going on with the readlink command?

Ubuntu 12.04 (precise)
2.6.38-8-generic
Intel(R) Core(TM) i5 CPU 650 @ 3.20GHz

[Ralph Corderoy (ralph-inputplus)]

It's not a good idea for us all to search through the forums and possibly read different material. Please state the problem here and give a direct link to the forum thread if you think it would be helpful background.

[C de-Avillez (hggdh2)]

Thank you for opening this bug and helping make Ubuntu better.

Additionally, 'readlink' _is_ available on precise, and it does accept a '-f'. Please provide:

1. the command run, and the full output.
2. the output of 'readlink --version'

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[jpvrlaone (jpv4433)]

Reuested info follows plus error messages listed when ran as root and user.
Maybe

# readlink --version
readlink (GNU coreutils) 8.13
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Dmitry V. Levin.

MORE >>>
AS ROOT>
# readlink -f "$0"readlink: invalid option -- 'u'
Try `readlink --help' for more information.

AS USER >
$ readlink -f "$0"readlink: invalid option -- 'b'
Try `readlink --help' for more information.

BELOW IS
# ./install

DEFAULT_INSTALL_PATH="/opt/pcdir"
+ DEFAULT_INSTALL_PATH=/opt/pcdir
DEFAULT_RUN_USER="root"
+ DEFAULT_RUN_USER=root
DEFAULT_RUN_GROUP="root"
+ DEFAULT_RUN_GROUP=root
RUN_LEVELS=(2 3 4 5)
+ RUN_LEVELS=(2 3 4 5)
INSTALL_AS_SERVICE="y"
+ INSTALL_AS_SERVICE=y
SCRIPT=`readlink -f "$0"`
readlink -f "$0"
++ readlink -f ./install
+ SCRIPT=/opt/pcdir/install
INSTALLDIR=`dirname "$SCRIPT"`
dirname "$SCRIPT"
++ dirname /opt/pcdir/install
+ INSTALLDIR=/opt/pcdir

[jpvrlaone (jpv4433)]

Sorry but I don't understand what I am not being clear about other than I appear to not be  following the problem reporting protocol.

I probably stems from a misunderstanding of the readlink command's syntax as used in a script that was failing---readlink -f "$0".
When I tested it outside the script I got incorrect flag usage errors.

________________________________
 From: Ralph Corderoy <email address hidden>
To: <email address hidden>
Sent: Monday, May 14, 2012 11:30 AM
Subject: [Bug 999207] Re: what is the operative readlink command?

It's not a good idea for us all to search through the forums and
possibly read different material.  Please state the problem here and
give a direct link to the forum thread if you think it would be helpful
background.

** Changed in: coreutils (Ubuntu)
       Status: New => Incomplete

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You received this bug notification because you are subscribed to the bug
report.
https://bugs.launchpad.net/bugs/999207

Title:
  what is the operative readlink command?

Status in “coreutils” package in Ubuntu:
  Incomplete

Bug description:
  I stumlbed accross a problem where a script  kept failing when running the readlink command.
  It did not like the use of the -f flag which is supported in the man page.  I got past the problem using  /usr/lib/klibc/bin/readlink  found through a search of the system.  More details can be found in the forum using the tag "readlink".
  What is going on with the readlink command?

  Ubuntu 12.04 (precise)
  2.6.38-8-generic
  Intel(R) Core(TM) i5 CPU        650  @ 3.20GHz

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/coreutils/+bug/999207/+subscriptions

[Ralph Corderoy (ralph-inputplus)]

When running the ./install script it seems to me that readlink works correctly, do you agree?

Running readlink at the command line and passing it $0 might result in the errors you are seeing depending on the value of $0. Please try

    printf '<%s>\n' "$0"
    readlink -f -- "$0"

The pasting of your terminal session above is a bit corrupted; readlink's errors appear on the same line as your command. It helps us if we see precisely what you entered and saw in response. So for the above, I see

    $ printf '<%s>\n' "$0"
    </bin/bash>
    $ readlink -f -- "$0"
    /bin/bash
    $

[Ralph Corderoy (ralph-inputplus)]

Not a bug. Reporter has clarified in original Question that $0 at the command line was passing -bash to readlink(1).

[jpvrlaone (jpv4433)]

I agree that the expanded install script w(use of set -vx) worked with the readlink command.

But somehow things got fuzzy and I hate to reinstall the running software monitoring tool to reenact the crime since I hate for you and me to spend more time on this.

I made a closing entry in the bug about the $0 agrument.

THANKS FOR YOUR INTEREST

________________________________
 From: Ralph Corderoy <email address hidden>
To: <email address hidden>
Sent: Monday, May 14, 2012 5:53 PM
Subject: [Bug 999207] Re: what is the operative readlink command?

When running the ./install script it seems to me that readlink works
correctly, do you agree?

Running readlink at the command line and passing it $0 might result in
the errors you are seeing depending on the value of $0.  Please try

    printf '<%s>\n' "$0"
    readlink -f -- "$0"

The pasting of your terminal session above is a bit corrupted;
readlink's errors appear on the same line as your command.  It helps us
if we see precisely what you entered and saw in response.  So for the
above, I see

    $ printf '<%s>\n' "$0"
    </bin/bash>
    $ readlink -f -- "$0"
    /bin/bash
    $

--
You received this bug notification because you are subscribed to the bug
report.
https://bugs.launchpad.net/bugs/999207

Title:
  what is the operative readlink command?

Status in “coreutils” package in Ubuntu:
  Incomplete

Bug description:
  I stumlbed accross a problem where a script  kept failing when running the readlink command.
  It did not like the use of the -f flag which is supported in the man page.  I got past the problem using  /usr/lib/klibc/bin/readlink  found through a search of the system.  More details can be found in the forum using the tag "readlink".
  What is going on with the readlink command?

  Ubuntu 12.04 (precise)
  2.6.38-8-generic
  Intel(R) Core(TM) i5 CPU        650  @ 3.20GHz

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/coreutils/+bug/999207/+subscriptions