Hi guys,
I'm a newbie to shell script. I have to write a shell script that is supposed to give me a date which should be older than the current date when I supply "no. of days" as a command line parameter to the script.
(i.e)., if I am giving the no. of days value as 305, the script should... (5 Replies)
the following bash script is not working in fedora-11 Could anyone help me please?
#!/bin/bash
if
-ne 0];then
echo " you are in root"
else echo " you must be in root -su mode??"
fi
exit (2 Replies)
Hello,
I have two files. File1 or the master file contains two columns separated by a delimiter:
a=b
b=d
e=f
g=h
File 2 which is the file to be processed has only a single column
a
h
c
b
What I need is an awk script to identify unique names from file 2 which are not found in the... (6 Replies)
I am compiling a synonym dictionary which has the following structure
Headword=Synonym1,Synonym2 and so on, with each synonym separated by a comma.
As is usual in such cases manual preparation of synonyms results in repeating the synonym which results in dupes as in the example below:... (3 Replies)
Hi,
I have the following command in place
nawk -F, '!a++' file > file.uniq
It has been working perfectly as per requirements, by removing duplicates by taking into consideration only first 3 fields. Recently it has started giving below error:
bash-3.2$ nawk -F, '!a++'... (17 Replies)
Hello,
I have a large amount of data with the following structure:
Word=Transliterated word
I have written a Perl Script (reproduced below) which goes through the full file and identifies all dupes on the right hand side. It creates successfully a new file with two headers: Singletons and Dupes.... (5 Replies)
Hoping for some assistance.
my source file consists of:
os, ip, username
win7, 123.56.78, john
win7, 123.56.78, paul
win7, 10.1.1.1, john
win7, 10.2.2.3, joe
I've been trying to run a script that will only return ip and username where the IP address is the same and the username is... (3 Replies)
Hello,
I have a database of name variants with the following structure:
variant=variant=variant
The number of variants can be as many as thirty to forty.
Since the database is quite large (at present around 60,000 lines) duplicate sets of variants creep in. Thus
John=Johann=Jon
and... (2 Replies)
Perl script to merge cells
---------- Post updated at 12:59 AM ---------- Previous update was at 12:54 AM ----------
I am using below code to read files from a dir and print to excel.
open(my $in, '<', $file) or die "Could not open file: $!";
my $rowCount = 0;
my $colCount = 0;... (11 Replies)
Hello,
I have a script which removes duplicates in a database with a single delimiter
=
The script is given below:
# script to remove dupes from a row with structure word=word
BEGIN{FS="="}
{for(i=1;i<=NF;i++){a++;}for(i in a){b=b"="i}{sub("=","",b);$0=b;b="";delete a}}1
How do I modify... (6 Replies)
Discussion started by: gimley
6 Replies
LEARN ABOUT SUSE
dup3
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
#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 3.25 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 2008-10-09 DUP(2)