Code:
MY_STDOUT=`my-command`
MY_STDERR=`my-command >&2`
That is, i want to have to run my-command only once and get the same result. I've tried this:
Code:
YYY=$(XXX=`{ echo -n 111; echo 222 >&2; }` 2>&1); echo $XXX $YYY
where "{ echo -n 111; echo 222 >&2; }" is my-command. But it gives this output:
Code:
222
111
instead of "111 222". What's wrong in my script?
I'm trying to write a program that will fork a series of FTP sessions. For each session, there should be separate input and output files associated with stdin and stdout/stderr.
I keep reading how I should be able to do that with dup2() in the child process before the execl(), but it's not working for me. Could someone please explain what I've done wrong? The program also has a 30-second sniper alarm for testing and killing of FTPs that go dormant for too long.
The code: (ftpmon.c)
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
[code]....
The output:
$ ftpmon
Connected to gila-crstest.gilacorp.com (172.16.20.8).
220 (vsFTPd 2.0.1)
ftp> waitpid(): Interrupted system call
Why am I getting the ftp> prompt? If the dup2() works, shouldn't it be taking input from my script and not my terminal? In stead, it does nothing, and winds up getting killed after 30 seconds. The log file is created, but it's empty after the run.
I have a little complex Makefile system. A parent Makefile call dozens of Makefiles in subdirctories. And the subdirctory Makefile calles shell script to do real building. I want to grab all output this Makefile system generate. So, i employ "make 2>&1 > make.log". but not all output messages are filed into make.log. The message generated by sub-makefile called shell script cannot be recorded into make.log. And another curiouse thing is, if i launch "make 2>&1 > make.log" in a perl script, all output do be sent into make.log.
View 2 Replies View RelatedI want to output the stdout and stderr in a logfile,moreover i do want to log stderr also to a separate logfile, and print str to the screen I searched arround and tried:
Code:
$ command 2>&1 > log | tee -a log log.err
But then in log first the stdout appears, and then stderr.
Am having issues getting the output from a script to be logged in a file. I need the script to output both the stderr and stdout to the same text file.
At present I have the following script:
Code:
#!/bin/bash
echo TR3_1 > printers.txt
snmpget -v 1 -c public 10.168.**.* SNMPv2-SMI::mib-2.43.10.2.1.4.1.1 &>> printers.txt
[Code].....
I have several commands in a bash script, and in the middle of the script there are several commands whose output and error streams I want to redirect to a file. I think I could simply add '>> myfile.txt' to the end of every command, but is there a way to set it before that block of commands, then reset the streams to their original state at the end of that block?
View 1 Replies View RelatedI'm working on an application used for backup/archiving. That can be archiving contents on block devices, tapes, as well as regular files. The application stores data in hard packed low redundancy heaps with multiple indexes pointing out uniquely stored, (shared), fractions in the heap.
And the application supports taking and reverting to snapshot of total storage on several computers running different OS, as well as simply taking on archiving of single files. It uses hamming code diversity to defeat the disk rot, instead of using raid arrays which has proven to become pretty much useless when the arrays climb over some terabytes in size. It is intended to be a distributed CMS (content management system) for a diversity of platforms, with focus on secure storage/archiving. i have a unix shell tool that acts like gzip, cat, dd etc in being able to pipe data between applications.
Example:
dd if=/dev/sda bs=1b | gzip -cq > my.sda.raw.gz
the tool can handle different files in a struct array, like:
Code:
enum FilesOpenStatusValue {
FileIsClosed = 0,
FileIsOpen,
[code]....
Is there a better way of getting the file name of the redirected file, (respecting the fact that there may not always exist such a thing as a file name for a redirection pipe).
Should i work with inodes instead, and then take a completely different approach when porting to non-unix platforms? Why isn't there a system call like get_filename(stdin); ?
If you have any input on this, or some questions, then please don't hesitate to post in this thread. To add some offtopic to the thread - Here is a performance tip: When doing data shuffling on streams one should avoid just using some arbitrary record length, (like 512 bytes). Use stat() to get the recommended block size in stat.st_blksize and use copy buffers of that size to get optimal throughput in your programs.
I'm using libxml2 to handle/manipulate some XML files. In order to check the consistency of a XML file, I have a DTD and I'm using the xmlValidateDtd method to compute the check.
However, when an error occures during the check (for example an attribute is missing in a XML tag), then libxml2 writes the error on the stdout/stderr. For exemple:
Code:
/home/XML/FreeFour.xml:18: element CA: validity error : Element CA does not carry attribute maxlength
The method return the right result (true or false depending on the check result), but occurring errors are written on the stdout/stderr, and I actually don't want that.
I have a script where I want to redirect stdout to the terminal and also to a log file aswell as redirecting stderr to the same log file but not the terminal.I have the following code which I found on the net which redirects both stderr and stdout to a file and the logfile,
Code: if [ -p $PIPE1 ]
then
rm $PIPE1
[code]...
Can I use qDebug() to print out stderr messages? If I just use qDebug() << stderr; I get hex output.
View 1 Replies View RelatedI am trying to parse a line from a file and place the values into separate variables:
input.txt:
Code:
CreateVegaFeed-20110928-before-skip-start
this is the code i have done so far:
Code:
$input_file="input.txt"
INPUT_FILE=`cat $input_file`
for i in $INPUT_FILE
[Code].....
I have a problem with snmp answers being empty or having spaces.
What I already have:
#get all interface indexes (if you wonder - I'm working for a cable company and different cablemodems have different number and types of interfaces):
The problem is the physical address which is sometimes empty and the description which has spaces. So I'm doing 2 snmpgets which is slower than 1 snmpget (sometimes I have up to 18 interfaces).
I'm trying to explain it a bit simpler.
Interface 5 gives me back the following lines:
Ethernet CPE Interface
Now the first line should go into variable ifadm,
2nd line should go into variable ifoper,
3rd line should go into variable ifspeed,
4th line should go into variable iftype,
5th line (which is empty) should go into variable ifphys and finally
6th line (which has spaces) should go into variable ifdescr
Trying to do a simple bash script, and having some issues. I am relatively new to bash, and did my best to search, but idk what exactly to search for.
Doesn't work code...
I'm trying to create a separate thread for my program which basically polls using the read command. However this new thread seems to block the main thread, anyone know why this could happen.
In main I call this function pthread_create(&mainEventThread, NULL, GenericEventThread, NULL);
which calls
/*New threads start function */
void *GenericEventThread()
{
short int i, nError = -1;
[Code]...
I've used pthread_self to check that a new thread is being created, so why is the while loop in one thread blocking the main thread from running, I haven't used the join function anywhere in my code.
mkvmerge -o <filename without extension>_TV.mkv -S <filename> && mkvextract tracks <filename> 3:<filename without extension>.*** && perl /home/brian/Desktop/ass2srt.pl <filename without extension>.*** && rm <filename without extension>.***
Doing these commands for multiple command line file inputs is the goal. So I can just type ./script.sh *.mkv in my terminal.This is what I have so far, but it doesn't work whatsoever.
this might be an interesting one for the bash scripting gurus. I seem to break my teeth on it. The mission:- do a dd over ssh to trasnfer an image to another host- capture the dd PID on the other side- send a USR1 kill signal to it- capture that output on the original host It goes wrong on the last part. This is what I have before that step:dd if=image.gz | gzip -d | ssh host2 "dd of=/dev/vg1/lv1" &PID=`ssh host2 ps aux |grep dd|grep lx05|awk '{ print $2 }'`when I do "ssh host2 kill -USR1 $PIDI get nice outputs to the screen. When I replace the first line with:dd if=image.gz | gzip -d | ssh host2 "dd of=/dev/vg1/l01 2>/tmp/output.txt" &the dd command seemd to die. I suspect a problem with the pipe, since this does work when executing locally on a host without piping.
View 4 Replies View RelatedI have seen a post where someone was explaining the virtuality of stdout and stderr and that it can be redirected with e.g. 2>file.txt but this apparently is not working for me!
I have a CUPS filter with fprintf(stderr,...)
i have this error when i tried to compil a program :
[Code]...
Is it possible to redirect stdout and stderr from one terminal say /dev/pts/2 to another /dev/pts/3?
I tried the following:
Code:
/dev/pts/2 2>&1 /dev/pts/3&
Then when I run a command the process stops.
Coming from Debian Sid and KDE, I am used to K3b and the problems during verify. Now with Fedora 11 and Brasero I'm also getting errors:
BraseroReadom stderr: Error trying to open /dev/sr0 exclusively (Device or resource busy)... giving up.
BraseroReadom stderr: WARNING: /dev/sr0 seems to be mounted!
BraseroReadom stderr: readom: Device or resource busy. Cannot open '/dev/sr0'. Cannot open SCSI driver.
[code].....
After going back and adding my user to cdrom and other groups, changing authorizations et.al., I am still getting errors that I don't have permissions to use the drive. I've read through forums and bug reports and find out that my problem isn't unique. Like with K3B, does the failure during verify usually leave me with a good burn anyway? Does anyone know of a gui burner that doesn't have the verify problem? Or, should I go back to burning on cli with wodim?
I have a Linux program which can write information to stdout and stderr.
I have a shell script which redirects that output to a file in /var/log. (Via >> and 2>&1.)
Is there a way to make that log file rotate? (max size, then switch to a different file, keep only a limited number of files)
I've seen a few answers which talk about the logrotate program, which sounds good, but they also seem to be focused on programs which are generating log files internally and handle HUP signals. Is there a way to make this work with a basic output redirection script?
I want to parse my mail log file and reuse the results but I'm having a hard time structuring the syntax. Something like:
Code:
grep hostname /var/log/mail.log |
grep NOQUEUE: |
sed -e 's/hostname postfix/smtpd/[[0-9]*]: //g'
at this point I want to redirect what I have in hand to a file but also ... fork? or split? whatever the term, to continue onward so that I can pipe the results further into wc -l or sort or programX. without having to re-loop through that huge log file.
I have a process which logs output to log.txt. If I want to see the process's status in real-time, is there a way to echo that output to stdout instead of opening the log in a text editor and constantly reloading?
View 3 Replies View RelatedI want to keep a trace of the URL I visit, so I use a command line like this:
tcpdump -ien1 -v -X 'tcp port 80' | sed -nl
's/^.0x[0-9a-f]{4}:.{43}(.)$/1/p' |perl break.pl |perl -pe
's/(GET|POST).(.*?).HTTP/1....Host:.([a-zA-Z._0-9-]*)../"
BEGURL
[Code]....
I also tried redirecting stdout and stderr to /tmp/out, it's still empty. The file has write access. I have no idea what it can be. Is there anything else than stdout and stderr?
In this example, why does blacklist end up in the file blacklist and $a end up in stdout?
[code]...
The desired result is to have a file containing the results of lsmod which had the first word on the line beginning with snd_ copied into another file preceded by the word blacklist.
do you know of a way to redirect stdout during boot time to have a log of the entire process?
I have a remote server which is not booting and I would like to know at which point it gets stucked, what could I do?
I want to have the output of a program go to 2 different files but not going to standard out. Is there a way to do this in bash? I know that in Z shell its really easy. omething like: Code: echo "test" >> file1 >> file2 Would work. But in Bash it doesn't seem that easy. I know that tee will send the output to 2 files but it also sends it to STDOUT.Something like:Code: echo "test" | tee -a file1 file2 Would put the word "test" in file1, file2, and STDOUT. Is there a way to just send the output to file1 and file2?
View 2 Replies View RelatedWhy doesn't this work?
Code:
cat | myvar=$(</dev/stdin) <<EOS
This is some content
EOS
echo "$myvar"
i have also tried several variants of cat in place of the redirection.
Code:
$(cat -)
$(cat)
$(cat /dev/stdin)
None of the variants print "This is some content"
I have a version that works:
Code:
myvar=$(cat <<EOS
This is some content
EOS
)
echo "$myvar"
but i don't like the syntax and it doesn't play nice in my editor with code folding.
I'm piping stdout from mplayer to awk, but the output stutters.
Code: Select allmplayer audiofile.m4a 2>&1 | awk -vRS="
" '$1 ~ /A:/ {print $0; fflush();}'
Instead of a steady output of lines to the terminal, output only occurs after a few seconds, between 6 or 12. This happens whether the input is from mplayer or avconv/ffmpeg. This never used to happen (a few years ago) so I wondered whether an awk update caused this to happen.
I am writing a script that calls a program which writes a lot of lines to stdout continuosly. If the last line in stdout has some regex, THEN, certain variables are updated. My problem is that I don't know how to do that.
A simplified example would be (it's not my exact case, but it I write it here to clarify): suppose I issue a ping command (which writes output to stdout continuously). Every time that the response time is t=0.025 ms, THEN, VARIABLE1=(column1 of that line) and VARIABLE2=(column2 of that line).
I think the following code would work in awk (however, I want the variables in bash and I don't know how to export them)
Code: Select allping localhost |awk '{ if ( $8 == "time=0.025" ) var1=$1 var2=$2}'
In the previous code, awk analyzes each line of the output of the ping command as soon as it is created, so the variables $var1, $var2, ... are updated at the appropriate time. But I need the "real-time" updated values of $var1, $var2 in bash, for later use in the script.