Software :: Redirect Stdout To File Produces Blank File
Dec 27, 2008
I cannot redirect output from commands such as iptables, iptables-save, and ifconfig. For example, any of the following DOESN'T work ( as root ):
Code:
iptables > tmp
iptables-save > tmp
ifconfig > tmp
The file tmp is ALWAYS blank, that is, 0 bytes in size. Wackier things DO work, such as:
Code:
echo "`iptables-save`" > tmp
iptables-save | tee tmp
Other commands like:
Code:
ls > tmp
DO work as expected.
Note that this problem happens regardless if I log-in remotely via ssh or locally on the computer in question. I am clueless as to what is causing this. Any ideas?The box is running 2.6.25-14.fc9.i686 and boots to runlevel 3. The modifications I've made to the box since installing the OS are things like compiling/installing latest OpenSSH,OpenSSL,httpd,BerkeleyDB,subversion,zlib etc -- nothing really out of the ordinary I'd say.
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.
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,
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?
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?
I 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 $a end up in stdout?
[code]...
The desired result is to have a file containing the results of lsmod which had the first word on the line beginning with snd_ copied into another file preceded by the word blacklist.
I am trying to grep multiple numbers from file, grep does have the -f option for that.
Code: grep -f <`seq 500 520` /etc/passwd I know this could be done with
Code: for i in `seq 500 520`; do grep "$i" /etc/passwd; done But my question is fare more behind this example. It is possible to redirect one command output which will be treat as a content of file for another command ?
I have a command line server that logs to stdout, which I start along the lines of ./server > log.txt
What I want to do is limit the size of log.txt, without modifying the server.
I am assuming there must be some kind of tool already that lets me do this, something like where I can pass in my server, the output file and a size limit? If so, can anyone enlighten me?
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.
I'm writing a script to execute bash commands in the PHP CLI. I would like to suppress errors from bash and write my own error message if an error occurs. So far I have this (assuming log.txt doesn't exist!):
Code:
tac log.txt 2>/dev/null
Which works as expected, tac kicks up an error but the error is suppressed, but when I use this:
Code:
tac < log.txt 2>/dev/null
I get:
Code:
bash: log.txt: No such file or directory
The tac error is suppressed but bash still gives me a dirty error.
I am again struggling to make a script work, but hey, it is fun, I am learning new things. I discovered the set -x option which was, for me, like the second coming. Still, what I am not able to do is redirect ALL output to a (log) file, including what is produced by the -x setting. Let's assume a very simple script: Code: #!/bin/bash set -x source="/home/atelier/Bureau/" ls -la $source and I am running it as . test.sh >> /var/log/test.rmcb.log
The result of ls goes inded into the log file, but the rest still shows on the console where I am running the script: Code: ++ source=/home/atelier/Bureau/ ++ ls --color=auto -la /home/atelier/Bureau/ Is there a way to redirect EVERYTHING to the log file ?
I want to redirect the output of a command to a file, but not at the end of the file, but after a line. Do you know how can I do it?
Something like:
cat file_a | grep some_text >> resulting_file
# in this file I need to place the output from grep, but not at the bottom of resulting_file, like it would normally happen, but after line .. 3 , for example
I'd like to redirect the output to a file and to the console. I know about tee but the issue is that it waits until the first process finishes.e.gecho "hello world" | tee test.txtfirst calls echo and then tee.Is there a way to redirect "on the fly" ?
I multi-boot several Linux distributions with an assortment of additional data partitions. I get frustrated whenever fsck is forced during boot. (It ONLY happens when I'm in a hurry don't you know...) So I wrote a script to automate forced fscking when I do have the time. (And/or while I'm doing something else in another workspace.
Because I multi-boot, I've learned that udev doesn't always assign the same device name to each drive for all distributions. I've had the same partition identified as hda5, sda5, & sdb5 by different distributions (without doing anything to affect the boot order) So my solution is to keep a list of partitions in a specific file on each distro with valid device names according to that distribution's udev process. Actually I'd use LABEL= instead but the labels don't show up in /etc/mtab, and I like to make sure a partition isn't mounted before I try to fsck it.
I can make this work in a for loop using cat. But I've seen so many things about NOT using cat that I wanted to rebuild my script. I can make this work with a redirect instead of cat via a while loop, But I "LIKE" old style for loops. But I can't seem to find a way to make a redirect work with one. I thought this might make a good first �LinuxQuestions.org� question. I'm also open to any other suggestions on better/alternative methods... Is it possible to redirect from a file into an actual for loop?
My script is as follows:
Code:
#!/bin/bash # FsckEm I script to force file system checking on unmounted ext2/ext3/ext4 # partitions in preselected list. FsckEm accepts no options. Partition
I was trying to redirect the output of two variables to different columns of a .csv file in MS excel like this,
Code: echo "$a $b" > abc.csv But I am getting both $a and $b in the same column, is there anything I can use instead of to move the value of $b to the next column? Or is there a good different approach to do it?
I'm sure this is something simple, but I've googled all over and can't find the answer for the life of me. I've got an apache server and I need to redirect all requests to HTTPS in the same domain, except for 1 html file the load balancer hits and needs to get a 200 on. Can anyone point me to some documentation or show me what I need to add to the httpd.conf file to get it working properly?
I'm trying to set up a framework where people connected to same wifi connection can enter a local site for developing purposes.I want them to be thrown to a local copy (development copy of the site) when they type in www.development.loc in the browser.I don't want to connect the world, only people connected to my wifi.Anyone willing to help by stating what I need to edit to :1. Allow me to access local copy of site that's on computer (located : /var/www/developmentsitename/) using www.development.loc in browser./and2a. What do I edit to create the server accessible by other computers connected to same wifi connection. 2b. If another computer can connect to this site now, can we create a virtual desktop setting in which workers can work as if they have their own partition on the server to work on and upload work onto the development server.
I booted to command line only and entered the following command: Sudo Xorg -configure > xorglog.txt
the command seems to run just fine and does create a new xorg.conf.new file but I would like to see all the output of the Xorg -configure command but it just scrolls by too fast and I can't go back to see it. Hence this is why I'm trying to do the > . It seems to ignore the >.
I have a python script that when run outputs to screen.
eg. ./international_sms_check.py 0403000511 919227434827 TS 21 check ok TS 22 check ok sms successfully delivered from 61403000511 to 919227434827 But when I try:./international_sms_check.py 0403000511 919227434827 > test
The file test is created but there is nothing in it.if I try ls > test this works fine with output of ls redirected to file test.
I have got a script with an outer and inner loop. The inner loop issues loads of echo's which need to be redirected to a log file determined by the outer loop. The obvious solution is to redirect every echo to >$LOG and set LOG in the outer loop.
Code:
for f in $FILES ; do LOG=<logfile> for l in $LINES ; do
[code]....
it is possible to map stdout to $LOG in the outer loop without having to redirect every subsequent individual command output?
I have this script in the past for csh: Code: ./a.out |& tee prints.txt which will redirect all printfs in the C program to the prints.txt file and at the same time show them in the console. How do you do this in bash? I have seen this, [URL] but it does not work for my bash and sh shells. It says:
Code: -bash: syntax error near unexpected token `&' and Code: -sh: syntax error: unexpected "&"
I need to redirect through a .htaccess file in my root folder. The redirect needs to be done from http://www.department.univeristy.edu/reuir to a different server [url]. I am having trouble in determining the pattern that is required for it to take effect.
