$ ls imafile idontexist 2> >(tee err >outanderr) | tee -a outanderr >/dev/null
has created problems to someone, so it isn't safe.
Thinking it were safe confused me.
Of course when there is only one command, as in
Code:
command >file 2>&1
the writes are sequential, so there cannot be problems.
When there are many (sub)processes, created by pipes or command substitution or whatever else, all concurrently writing on the same file, I cannot see a clear way to be sure they won't overlap - using only the shell tools: /var/log/syslog works flawlessly, but there's a daemon in control, Which I think has its own importance.
Depending on the scheduler, on the number of CPUs and maybe on many other things, some solutions may seem to work here for a while, but don't work there.
Beside some awful workarounds with a very tiny field of application, like something that:
Code:
( ls imafile idontexist 2>&1 >&3 | { sleep 1; tee err >&3; } ) 3>outanderr
I can't think of any real solution. But since I know very little at all about these black boxes we call "computers", I wouldn't be surprised to be totally wrong.
Thanks to anyone reading all this awkward stuff.
--
Bye
Hi gurus.
I implemented sudo and have the following in my sudo config file
***************
# User alias specification
User_Alias VENDOR = user1
# User privilege specification
VENDOR ALL = NOPASSWD: /bin/, /sbin/, /usr/local/bin/, \
!/bin/su,... (1 Reply)
I've written a small script to replace certain words in all the the files in a directory.
#!/bin/sh
#Get list of files to be edited
file_list=`ls -p`
for i in $file_list
do
echo "Processing $i"
alteredi=`echo "$i" | sed -e 's/\//d/'`
if
then
if
then
#actual altering (2 Replies)
i 've noticed the following difference between freebsd cp and gnu cp
from the freebsd cp man page:
-R ... If the source_file ends in a /, the contents of the directory are copied rather than
the directory itself. ...
on gnu cp from the man pagewhile on gnu cp manpage:
‘-r'... (2 Replies)
Hello,
I am getting an infinite loop from a script in Linux.
Here is the last version of the script in question. As you can see I tried to define everything properly:
#!/bin/ksh
# Script to loop over a series of dates
set -ex
typeset -i start_date=20090701
typeset -i... (2 Replies)
I have these two files in current dir:
oos.txt
oos_(copy).txt
I execute this find command:find . -regex './oos*.txt'And this outputs only the first file (oos.txt)! :confused:
Only if I add another asterisk to the find find . -regex './oos*.*txt' do I also get the second file... (7 Replies)
I am little bit confused by the behaviour of rm in Ubuntu.
It seems that as a regular user I can delete files owned by another user even when the permissions are set to 644.
Here is an example:
cjohnson@carbon:~/test$ sudo touch testfile
cjohnson@carbon:~/test$ ls -al
total 8
drwxr-xr-x... (2 Replies)
fg = foreground bg = background
I have a cobol program that I start with a very simple script.
The script is not at fault as it has not changed and the program worked in fg and bg before.
I have altered the logging in the program and moved my cursor declare to working storage.
The program runs... (6 Replies)
I see strange results when sorting with -n options and I wander if somebody can explain it.
Input file and two results:
$ cat aa
14
-1
11
-1
0
-1
0
$ sort -u aa
-1
0 (1 Reply)
Discussion started by: migurus
1 Replies
LEARN ABOUT LINUX
rbash
RBASH(1) General Commands Manual RBASH(1)NAME
rbash - restricted bash, see bash(1)RESTRICTED SHELL
If bash is started with the name rbash, or the -r option is supplied at invocation, the shell becomes restricted. A restricted shell is
used to set up an environment more controlled than the standard shell. It behaves identically to bash with the exception that the follow-
ing are disallowed or not performed:
o changing directories with cd
o setting or unsetting the values of SHELL, PATH, ENV, or BASH_ENV
o specifying command names containing /
o specifying a file name containing a / as an argument to the . builtin command
o specifying a filename containing a slash as an argument to the -p option to the hash builtin command
o importing function definitions from the shell environment at startup
o parsing the value of SHELLOPTS from the shell environment at startup
o redirecting output using the >, >|, <>, >&, &>, and >> redirection operators
o using the exec builtin command to replace the shell with another command
o adding or deleting builtin commands with the -f and -d options to the enable builtin command
o using the enable builtin command to enable disabled shell builtins
o specifying the -p option to the command builtin command
o turning off restricted mode with set +r or set +o restricted.
These restrictions are enforced after any startup files are read.
When a command that is found to be a shell script is executed, rbash turns off any restrictions in the shell spawned to execute the script.
SEE ALSO bash(1)GNU Bash-4.0 2004 Apr 20 RBASH(1)
08-30-2012
