The standard output stream (stdout) is the stream where a program writes its output data.
Questions tagged [stdout]
4740 questions
2
votes
2 answers
How can I print to stdout from within a trap called during eval
I expected the following script to print This is redirected to 'output'. when I press ctrl+c:
#!/bin/bash
trap_function(){
trap '' EXIT INT TERM
echo "This is redirected to 'output'."
touch this_will_exist
}
trap trap_function EXIT INT…
katosh
- 372
- 4
- 12
2
votes
1 answer
dup2 to redirect stdout and stderr to another file descriptor
i have a call like this.
int fd[2];
pipe(fd)
and then
dup2(fd[WRITE],STDOUT_FILENO)
is there a way to use the dup call to duplicate both 1 and 2 to fd[WRITE]?
Prasanth Madhavan
- 12,657
- 15
- 62
- 94
2
votes
1 answer
redirect stdout and stderr to file and stderr to screen while preserving output order
I want to redirect stdout and stderr to a file while preserving the order of output but then also show stderr to screen. I see a lot of questions discuss…
IMTheNachoMan
- 5,343
- 5
- 40
- 89
2
votes
1 answer
Golang add custom os.File to os.Stdout
I'm trying to write output to a file whenever I print something to the console. There didn't seem to be any nice examples out there using a continuous stream, but rather reading a single value so I came up with the following code:
package…
user3672215
2
votes
1 answer
Redirection of stdout from a SWIG-wrapped C++ class to a non-file python object
I'm trying to redirect the output from a SWIG-wrapped C module to a python class.
The SWIG caller is a python class which already has sys.stdout overwritten in the following way:
with _redirect_streams():
my_C_function(sys.stdout)
try:
…
sherve
- 300
- 2
- 10
2
votes
2 answers
How to tell if my python program has written anything to sys.stdout or not (within the same program)?
I'm making a program that has different control flows depending on whether anything was written to sys.stdout or not. I made this program first in my Mac and I could do this
pos = sys.stdout.tell()
exec(some_code, globals)
if pos ==…
user5538922
2
votes
3 answers
Python: piping pcap file to stdout gives error
I am trying to pipe the output of xz to a custom python script:
xz -cd file.pcap.xz | myscripy.py
However, I get an error when the script attempts to run this line:
#!/usr/bin/env python2.7
from __future__ import print_function
import…
Ilia
- 534
- 3
- 21
2
votes
0 answers
Can't parse tcpdump output correctly
I'm trying to run this command: sudo tcpdump "ether proto 0x888e and ether host " -I -w -U -vvv -I -w ~/Desktop/handshake.cap which works perfectly in terms of its function, however, when I run the command, I get the following…
Rocco
- 165
- 4
2
votes
5 answers
How to get perl code output to STDOUT/STDERR and a file, in realtime and cross-platform?
I need to get the output of normal Perl code to the screen and into a logfile at the same time. However a problem is that the runtime of the tool can be hours. Using Capture::Tiny's tee that means the log file will only be written to once the script…
Mithaldu
- 2,393
- 19
- 39
2
votes
2 answers
Which is better way to write out and err of python
I am writing python in Linux. I want to write the python output and error into different files than output them on the console.
Say if I have this python file example.py:
print('console output')
print(1/0)
I tried different way.
1. By executing…
Echan
- 1,395
- 14
- 15
2
votes
1 answer
How to capture the tags applied by git decorate
What goes on here? Why are the two outputs different?
$ git log --oneline -n1
7dbee6d (HEAD -> master, origin/master, origin/HEAD) some commit msg
$ git log --oneline -n1 | head
7dbee6d some commit msg
The piping to 'head' was the simplest example…
user3729611
- 385
- 3
- 9
2
votes
4 answers
Redirecting all commands stdout/stderr to a log file from within a script
I've read how to log certain scripts or commands individually, but nothing on how to log all commands from within a BASH shell. What I want to do is:
User runs script. (script logs stdout/stderr from now on to a logfile)
User does other stuff/runs…
Dororo
- 3,420
- 2
- 30
- 46
2
votes
1 answer
How to hide return value for process.stdout.write() in Nodejs REPL?
I'm doing some drawings in the terminal and want to hide the return value.
Example:
> process.stdout.write("Hello world");
Hello worldtrue
Thanks!
emcee
- 91
- 7
2
votes
1 answer
Communicate with external C program with Java using stdin and stdout
What I'm trying to do is launch the C program executable inside the Java application and allow them to communicate with each other using stdin and stdout. The C program will wait for a command from the java app and echo it back. I've tested the java…
Vince
- 21
- 1
- 2
2
votes
1 answer
Perl: Piping child stdout to parent process
In Perl, I can open a child process and pipe its output to the calling Perl script, like this:
open(my $cmd, '-|', 'ls') or die $!;
while (<$cmd>) {
print $_;
}
This prints the files in my working folder, e.g.:
> foo.txt
> bar.txt
> ...
But I…
dmc7z
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- 2
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- 15