Hi all hope you can help as I am going MAD!!! :eek:
The below is in a shell script but the redirection in the sed line does not work and outputs to the screen and the $fname_2 does note get created ?????
Can any one help ??
#!/bin/ksh
cd /app/
for fname in `ls -1 X*`
do
sed 1d $fname... (3 Replies)
Hi all,
I have the following script:
-------------------------------------------------
#SCRIPT TO CHECK WHO HAS ACCESSED THE LOG/FILE IN PAST 'N' MINUTES, AND MAIL ACCORDINGLY.
MYPATH="/clocal/mqbrkrs/user/mqsiadm/sanjay/"
MAIL_RECIPIENTS="vg517@dcx.com"
Subject="File accessed in last... (6 Replies)
Hi friends
I am facing one problem while redirecting the out of the stderr and stdout to a file
let example my problem with a simple example
I have a file (say test.sh)in which i run 2 command in the background
ps -ef &
ls &
and now i am run this file and redirect the output to a file... (8 Replies)
Hi
I am not if this is possible: is it possible in bach (or another shell) to redirect GLOBALLY the stdout/stderr channels to a file.
So, if I have a script
script.sh
cmd1
cmd2
cmd3
I want all stdout/stderr goes to a file. I know I can do:
./script.sh 1>file 2>&1
OR
... (2 Replies)
Hi,
I would like to avoid re-directing line by line to a file.
What is the best way to re-direct STDOUT to a file in a subshell?
Thanks in advance.
Cheers
Vj (1 Reply)
Hello
I read a lot of post related to this topic, but nothing helped me. :mad:
I'm running a ksh script with subshell what processing some ldap command. I need to check output for possible errors.
#!/bin/ksh
...
readinput < $QCHAT_INPUT |&
while read -p line
do
echo $line
... (3 Replies)
Hi All,
I am using centOS.
When I try to redirect STDOUT to a file, it ends up in getting some funny characters. For example ...
STDOUT of the command as follows.
$ ls
H3k27me3
H3k36me3
H3k4me1
H3k4me2
H3k4me3
H3k9ac
H4k20me1
$ ls >test
$ cat test
^ (1 Reply)
Dear all,
redirecting STDOUT & STDERR to file is quite simple, I'm currently using:
exec 1>>/tmp/tmp.log; exec 2>>/tmp/tmp.logBut during script execution I would like the output come back again to screen, how to do that?
Thanks
Lucas (4 Replies)
Dear all,
redirecting STDOUT & STDERR to file is quite simple, I'm currently using:
Code:
exec 1>>/tmp/tmp.log; exec 2>>/tmp/tmp.log
But during script execution I would like the output come back again to screen, how to do that?
Thanks
Luc
edit by bakunin: please use CODE-tags like the... (6 Replies)
Discussion started by: tmonk1
6 Replies
LEARN ABOUT LINUX
dup2
DUP(2) Linux Programmer's Manual DUP(2)NAME
dup, dup2, dup3 - duplicate a file descriptor
SYNOPSIS
#include <unistd.h>
int dup(int oldfd);
int dup2(int oldfd, int newfd);
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <unistd.h>
int dup3(int oldfd, int newfd, int flags);
DESCRIPTION
These system calls create a copy of the file descriptor oldfd.
dup() uses the lowest-numbered unused descriptor for the new descriptor.
dup2() makes newfd be the copy of oldfd, closing newfd first if necessary, but note the following:
* If oldfd is not a valid file descriptor, then the call fails, and newfd is not closed.
* If oldfd is a valid file descriptor, and newfd has the same value as oldfd, then dup2() does nothing, and returns newfd.
After a successful return from one of these system calls, the old and new file descriptors may be used interchangeably. They refer to the
same open file description (see open(2)) and thus share file offset and file status flags; for example, if the file offset is modified by
using lseek(2) on one of the descriptors, the offset is also changed for the other.
The two descriptors do not share file descriptor flags (the close-on-exec flag). The close-on-exec flag (FD_CLOEXEC; see fcntl(2)) for the
duplicate descriptor is off.
dup3() is the same as dup2(), except that:
* The caller can force the close-on-exec flag to be set for the new file descriptor by specifying O_CLOEXEC in flags. See the description
of the same flag in open(2) for reasons why this may be useful.
* If oldfd equals newfd, then dup3() fails with the error EINVAL.
RETURN VALUE
On success, these system calls return the new descriptor. On error, -1 is returned, and errno is set appropriately.
ERRORS
EBADF oldfd isn't an open file descriptor, or newfd is out of the allowed range for file descriptors.
EBUSY (Linux only) This may be returned by dup2() or dup3() during a race condition with open(2) and dup().
EINTR The dup2() or dup3() call was interrupted by a signal; see signal(7).
EINVAL (dup3()) flags contain an invalid value. Or, oldfd was equal to newfd.
EMFILE The process already has the maximum number of file descriptors open and tried to open a new one.
VERSIONS
dup3() was added to Linux in version 2.6.27; glibc support is available starting with version 2.9.
CONFORMING TO
dup(), dup2(): SVr4, 4.3BSD, POSIX.1-2001.
dup3() is Linux-specific.
NOTES
The error returned by dup2() is different from that returned by fcntl(..., F_DUPFD, ...) when newfd is out of range. On some systems
dup2() also sometimes returns EINVAL like F_DUPFD.
If newfd was open, any errors that would have been reported at close(2) time are lost. A careful programmer will not use dup2() or dup3()
without closing newfd first.
SEE ALSO close(2), fcntl(2), open(2)COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2010-09-10 DUP(2)