How to open, lock, write and close a file in ksh
How to open, lock, write and close a file in ksh
am 22.01.2006 04:40:16 von herbert
I am a beginner in shell scripting.
I have a question regarding file handling in shell script.
There is a perl script as follows:
open (WRITEFILE, ">>/user/test.html");
flock WRITEFILE, LOCK_EX;
print (WRITEFILE "test");
.....
print (WRITEFILE "
");
close WRITEFILE
If I want to change this to ksh script, how can I do it?
open(WRITEFILE, '/user/test.html')
flock WRITEFILE, LOCK_EX
I am not sure of write something into file
close WRITEFILE.
Can anyone help me with this?
Thanks
Re: How to open, lock, write and close a file in ksh
am 22.01.2006 21:25:35 von Bill Marcum
On 21 Jan 2006 19:40:16 -0800, Herbert
wrote:
> I am a beginner in shell scripting.
> I have a question regarding file handling in shell script.
> There is a perl script as follows:
>
> open (WRITEFILE, ">>/user/test.html");
> flock WRITEFILE, LOCK_EX;
> print (WRITEFILE "test");
> ....
> print (WRITEFILE "
");
> close WRITEFILE
>
> If I want to change this to ksh script, how can I do it?
>
> open(WRITEFILE, '/user/test.html')
"open" and "close" commands are usually not needed in shell scripts,
but when they are needed, files are opened and closed with redirection
commands like "exec >/usr/test.html" or "exec >&-"
> flock WRITEFILE, LOCK_EX
There is a flock command, but it is rarely included in Unix/Linux
distributions. In shell scripts, one usually uses a lock file or
directory, with the assumption that other scripts will test that before
writing the file.
until mkdir lock_dir; do sleep 1; done
> I am not sure of write something into file
Depending on the application:
echo something > $WRITEFILE
echo something >> $WRITEFILE
or
sed 's/oldstring/newstring/' $WRITEFILE > tempfile
mv tempfile $WRITEFILE
--
abuse me. I'm so lame I sent a bug report to
debian-devel-changes
Re: How to open, lock, write and close a file in ksh
am 23.01.2006 01:10:45 von herbert
Bill Marcum
Jan 22, 4:25 pm show options
Newsgroups: comp.unix.shell
From: Bill Marcum - Find messages by this author
Date: Sun, 22 Jan 2006 15:25:35 -0500
Local: Sun, Jan 22 2006 4:25 pm
Subject: Re: How to open, lock, write and close a file in ksh
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On 21 Jan 2006 19:40:16 -0800, Herbert
wrote:
> I am a beginner in shell scripting.
> I have a question regarding file handling in shell script.
> There is a perl script as follows:
> open (WRITEFILE, ">>/user/test.html");
> flock WRITEFILE, LOCK_EX;
> print (WRITEFILE "test");
> ....
> print (WRITEFILE "
");
> close WRITEFILE
> If I want to change this to ksh script, how can I do it?
> open(WRITEFILE, '/user/test.html')
"open" and "close" commands are usually not needed in shell scripts,
but when they are needed, files are opened and closed with
redirection
commands like "exec >/usr/test.html" or "exec >&-"
> flock WRITEFILE, LOCK_EX
There is a flock command, but it is rarely included in Unix/Linux
distributions. In shell scripts, one usually uses a lock file or
directory, with the assumption that other scripts will test that before
writing the file.
until mkdir lock_dir; do sleep 1; done
> I am not sure of write something into file
Depending on the application:
echo something > $WRITEFILE
echo something >> $WRITEFILE
or
sed 's/oldstring/newstring/' $WRITEFILE > tempfile
mv tempfile $WRITEFILE
-----------
Thanks for the reply but I don't understand the file lock stuff in your
reply.
until mkdir lock_dir; do sleep 1; done
How do I lock '/user/test.html' file? Can you please explain it again?
Re: How to open, lock, write and close a file in ksh
am 23.01.2006 09:11:21 von Stephane CHAZELAS
2006-01-21, 19:40(-08), Herbert:
> I am a beginner in shell scripting.
> I have a question regarding file handling in shell script.
> There is a perl script as follows:
>
> open (WRITEFILE, ">>/user/test.html");
> flock WRITEFILE, LOCK_EX;
> print (WRITEFILE "test");
> ....
> print (WRITEFILE "
");
> close WRITEFILE
>
> If I want to change this to ksh script, how can I do it?
>
> open(WRITEFILE, '/user/test.html')
> flock WRITEFILE, LOCK_EX
> I am not sure of write something into file
> close WRITEFILE.
>
> Can anyone help me with this?
[...]
You don't want to do it like that. A shell is not a programming
language, you have to think differently, you can't translate
word to word from another language.
--
Stéphane