Below is the scenario. Help is appreciated.
File1: ( 500,000 lines ) : Three fields comma delimited : Not sorted
1234FAA,435612,88975
1224FAB,12345,212356
File2: ( 4,000,000 lines ) : Six fields comma delimited (Last 3 field should match the 3 fields of File1) : Not Sorted :
... (13 Replies)
I have data, from which I want to grep for two fields. Only pull out the data if both the fields exist.
I have used: egrep --text "field1|field2" file > temp. This seems to be doing an OR. What I am after is an AND. (10 Replies)
I'm trying to find all modules that contain line feed characters. It shows up at ^M (Hex 0D0A). Does anyone know how to do a search for hex fields?
I tried doing "egrep ^M *.cbl", but that doesn't work.
Thanks! (3 Replies)
Hi,
I have a pipe delimited file. I am checking for junk characters ( non printable characters and unicode values).
I am using the following code
grep '' file.txt
But i want to ignore the name fields. For example field2 is firstname so i want to ignore if the junk characters occur... (4 Replies)
Hello,
I met a challenge to extract part of the table. I'd like to grep the first three matches based on field1 and field2. Input:
D A 92.85 1315 83 11
D A 95.90 757 28 3
D A 94.38 480 20 7
D A 91.21 307 21 6
D A 94.26 244 ... (6 Replies)
Hi there,
I have data with similar structure as this:
CHR START-SNP END-SNP REF ALT PATIENT1 PATIENT2 PATIENT3 PATIENT4
chr1 69511 69511 A G homo hetero homo hetero
chr2 69513 69513 T C . hetero homo hetero
chr3 69814 69814 G C . . homo homo
chr4 69815 69815 C A hetero . . hetero
is... (10 Replies)
Hi,
Below are the sample files. x.txt is from an Excel file that is a list of users from Windows and y.txt is a list of database account.
$ head -500 x.txt y.txt
==> x.txt <==
TEST01 APP_USER_PROFILE
USER03 APP_USER_PROFILE
TEST02 APP_USER_EXP_PROFILE
TEST04 APP_USER_PROFILE
USER01 ... (3 Replies)
Hi Experts,
I am working one one python script in version 3.x and 2.6. Need your support to complete it
Basically for both commands i have telnet to device and run command and then receiving input File 1 and File 2
I have two commands, need to grep data and output in csv file.
Next script/code... (0 Replies)
Discussion started by: as7951
0 Replies
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ipc::open2
IPC::Open2(3pm) Perl Programmers Reference Guide IPC::Open2(3pm)NAME
IPC::Open2 - open a process for both reading and writing using open2()
SYNOPSIS
use IPC::Open2;
$pid = open2(*CHLD_OUT, *CHLD_IN, 'some cmd and args');
# or without using the shell
$pid = open2(*CHLD_OUT, *CHLD_IN, 'some', 'cmd', 'and', 'args');
# or with handle autovivification
my($chld_out, $chld_in);
$pid = open2($chld_out, $chld_in, 'some cmd and args');
# or without using the shell
$pid = open2($chld_out, $chld_in, 'some', 'cmd', 'and', 'args');
waitpid( $pid, 0 );
my $child_exit_status = $? >> 8;
DESCRIPTION
The open2() function runs the given $cmd and connects $chld_out for reading and $chld_in for writing. It's what you think should work when
you try
$pid = open(HANDLE, "|cmd args|");
The write filehandle will have autoflush turned on.
If $chld_out is a string (that is, a bareword filehandle rather than a glob or a reference) and it begins with ">&", then the child will
send output directly to that file handle. If $chld_in is a string that begins with "<&", then $chld_in will be closed in the parent, and
the child will read from it directly. In both cases, there will be a dup(2) instead of a pipe(2) made.
If either reader or writer is the null string, this will be replaced by an autogenerated filehandle. If so, you must pass a valid lvalue
in the parameter slot so it can be overwritten in the caller, or an exception will be raised.
open2() returns the process ID of the child process. It doesn't return on failure: it just raises an exception matching "/^open2:/".
However, "exec" failures in the child are not detected. You'll have to trap SIGPIPE yourself.
open2() does not wait for and reap the child process after it exits. Except for short programs where it's acceptable to let the operating
system take care of this, you need to do this yourself. This is normally as simple as calling "waitpid $pid, 0" when you're done with the
process. Failing to do this can result in an accumulation of defunct or "zombie" processes. See "waitpid" in perlfunc for more
information.
This whole affair is quite dangerous, as you may block forever. It assumes it's going to talk to something like bc, both writing to it and
reading from it. This is presumably safe because you "know" that commands like bc will read a line at a time and output a line at a time.
Programs like sort that read their entire input stream first, however, are quite apt to cause deadlock.
The big problem with this approach is that if you don't have control over source code being run in the child process, you can't control
what it does with pipe buffering. Thus you can't just open a pipe to "cat -v" and continually read and write a line from it.
The IO::Pty and Expect modules from CPAN can help with this, as they provide a real tty (well, a pseudo-tty, actually), which gets you back
to line buffering in the invoked command again.
WARNING
The order of arguments differs from that of open3().
SEE ALSO
See IPC::Open3 for an alternative that handles STDERR as well. This function is really just a wrapper around open3().
perl v5.16.2 2012-10-11 IPC::Open2(3pm)