In shell, I execute "./ffmpeg -f h264 - | xxx"
Now I hope use execl function to execute above operations,
I call execl("/bin/sh", "sh", "-c", "./ffmpeg -f h264 - | xxx");
but ffmpeg doesn't work, it seems that "|" pipe don't work.
how could I solve this?
I've written a simple server in linux used fork to create a FIFO pipe.The server create two FIFO pipe.One for server read data from client and write data to client.Then another pipe for client read data from server and write data to server.When the server read data from a client used server-pipe and then write data to client.But ,if the client no read open the pipe,the server side write will be crashed because of a broken-pipe SIGPIPE. How to check whether the read side is opened?Or,how to catch the SIGPIPE,and then my server will still execute on,not crashed!!
View 5 Replies View RelatedCode:
#include <iostream>
using namespace std;
[code]...
I am doing some Linux kernel programming for my research project. I need to record the timestamp (by using cpuid and rdtsc) when an interrupt handler (top half) is first invoked. Due to the time critical nature of the problem itself, I have to do the timestamping inside the interrupt handler itself (the first operation when the handler is called). However, I understand that tasks that are not so time critical should be deferred to a tasklet function (bottom half) for processing because other interrupts are disabled in a (top-half) interrupt handler. I am currently out of idea on how I can pass the timestamp information that I have obtained in the interrupt handler to the corresponding tasklet function.
View 2 Replies View Relatedhow to generate excel charts from C, or if it's possible at all? For example, if I had 2 arrays that I wanted to export to excel and graph against each other. I know how to export it to a csv file, that's no problem, but I have no idea where to start with generating a graph of the data. I can't seem to find any examples anywhere. Just a simple example to show you what I mean: Code:
char arr1[] = {'a','b','c'};
int arr2[] = {10,20,30};
int main ()
[code]....
Does anybody know how to generate excel charts from C, or if it's possible at all?
For example, if I had 2 arrays that I wanted to export to excel and graph against each other. I know how to export it to a csv file, that's no problem, but I have no idea where to start with generating a graph of the data. I can't seem to find any examples anywhere.
I'd appreciate if someone could point me in the right direction.
Just a simple example to show you what I mean code...
I am having trouble getting some code to work. It takes an input file (csv) and converts it to an XLS. The problem is that I can't seem to get a header to be printed first...
Code:
use Spreadsheet::WriteExcel;
my $input = $ARGV[0];
[code]...
I have a LAMP based web hosting account (BlueHost). I have an existing simple MS Excel application which I would like to make it web based. However I am not sure what tools or features of PHP are out there that will aid me with this task. Here are some details:
1. I don't want to create an entire Excel program online. For that there are plenty of existing applications like Google Docs, MS's own online version of Excel, etc.
2. My current excel file uses some of the following excel functions:
a) SUM
b) Product Sum
c) Conditional Formatting (like changing font color if an amount is below a threshold, etc.)
d) Sorting (Date, Amount)
e) Drop Down Box to select pre-defined values
3. Ability to add/delete/modify a entry (row)
4. I don't care whether the application has the same look-n-feel as MS Excel.
As you can see it is a very simple home grown excel application with few basic mathematical functions. Here are some few thoughts that I have currently in my mind:
i) Just start coding intuitively as you would develop a normal web based application.
ii) Do (i) but use some of the PHP's excel oriented helper functions (COMs?) if there are any
iii) Use completely a different set of tools permitting that they run on LAMP environment.
I could have started with (i) but before making a costly mistake I thought I would get some opinion from the community to see if this is the right approach.
Are there any solutions by which linux-based web server frameworks (like zend or any other) can process data inside microsoft excel spreadsheets (*.xls)?
View 1 Replies View Relatedi am using linux for the first time. i have been given a project which will fetch data from csd(comma separated form) and ll display on d screen. i want a c program for linux which ll do the above given task. moreover i want the parameter file(such as location of file, file name,etc..) as a different file. so that i can access this program on any computer.
View 3 Replies View RelatedI have an Excel Spreadsheet which reports upon weekly performance. One portion of the worksheet looks at week over week increases /decreases. I've placed a number of image controls (15 in Total) next to cells which calculate week over week change. The image controls simply display an image depending on whether the value of the adjacent cell is positive or negative. So, here is my basic working IF statement:
Code:
Private Sub Worksheet_Change(ByVal UpDown As Range)
If Range("J26") > 0 And IsNumeric(Range("J26").Value) Then
Image1.Picture = LoadPicture("C:path oup_arrow.gif")
ElseIf Range("J26") < 0 And IsNumeric(Range("J26").Value) Then
[code]....
As you can see, this is pretty simple. What I'd like to do is find a way to loop through all 15 controls and avoid having 15 IF statements run on the Worksheet_Change() event. The cells containing the week over week values are all in the same column, but not continuous. Involved cells are: ("J26", "J27", "J33", "J34", "J35", "J36", "J37", "J38", "J39", "J40", "J42", "J43", "J44", "J45", "J46")
Looking for an open source solution to convert pdf file to excel document.
View 1 Replies View RelatedI want to declare a function in a function, but had no success till now, see the error code below and visit the project at sourceforge
[Code]...
I looked on the net for such function or example and didin't find anything, thus after having made one i guess it would be legitimate to drop it to see what others thinks of it.
#!/bin/bash
addelementtoarray()
{
local arrayname=$1
[code]....
I understand that $! is the PID of a command. For example:
Code: #!/bin/bash
myprogram &
echo "PID of myprogram is $!"
I'd like to send the output of "myprogram" to both console and to a log file using the "tee" command but I also want to store the PID of "myprogam". Something like this:
Code: #!/bin/bash
myprogram | tee ./logfile &
echo "PID of myprogram is $!"
The problem is that $! is now the PID of "tee" rather than the PID of "myprogram".
I am trying to automate some directory naming when we're manually running some scripts and are using tee to direct the output to a file (log). Right now this is what we do
Code:
./some_script.sh 2>&1 | tee /home/user/some_dir/logs/manual/some_script_20110216_1628.log
As a matter of laziness and keeping the log files consistently named, I'd like to create a function to pipe it to so that it's doing all the naming How I envision the command running
Code:
./some_script.sh 2>&1 | myfunc
And what the logfile name should look like (and in the right directory)
Code:
some_script_20110216-1628.log
I was thinking of adding a function to our profile to handle this. Just in testing I was trying to stream line right on the command line, but I'm having some difficulty in getting the name of the script that is pushing data over the pipe. Here is what I've tried
Code:
./some_script.sh 2>&1 | tee $(cd ../logs/manual; pwd)/$0_$(date +%Y%m%d)-$(date +%H%M).log
but that created a file named
"bash_20110216-1628.log"
For instance, suppose I want to pipe the output of ps -A to a gtkdialog table.
View 1 Replies View RelatedI want to pipe the output of ls in a folder to a file (lets call it test.txt) but when i do so, but when i do ls > test.txt in test.txt there is also test.txt (logical
View 4 Replies View RelatedI'm doing ping between 2 RH servers through a VPN site2site tunnel and in some times I got in the result pipe 2 and another pipe 3 as I mark it in blue color below.
e.g.
64 bytes from 192.168.1.10: icmp_seq=0 ttl=128 time=0.229 ms
64 bytes from 192.168.1.10: icmp_seq=1 ttl=128 time=0.287 ms
64 bytes from 192.168.1.10: icmp_seq=2 ttl=128 time=0.278 ms
[code]....
What's the difference between pipe 2 and pipe 3 and what's the meaning of it?
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 RelatedI have a small program that reads stdin from a pipe using fgets. Now fgets blocks for the first line but after that it will not block.
The code, my_echo.c -
int main(int argc, char **argv) { char buf [2000] ;
char* pc ; printf("hello ") ; while (1)
{ buf[0] = (char) 0 ;
pc = fgets(buf, sizeof(buf), stdin);
if (pc != NULL) printf("%s ",buf); } return 0; }
How its called
* In terminal window 1: ./my_echo < my_fifo
* In terminal window 2: echo "1234" > my_fifo
* In terminal window 1: prints hello then 1234.
* Checking with ksysguard or top shows that my_echo is consuming 40% of CPU time.
Adding a few printf's shows that the gets is not blocking and returns a null pointer.
* In terminal window 2: echo "qwerty" > my_fifo
* In terminal window 1 qwerty prints.
I want a read function that does in fact block so my program does not tie up CPU time, read does not block.
I'm looking for a way to detect whether or not a program has been called from pipe, e.g.
Code:
whatever | my_program
versus simply just being exectuated directly:
Code:
my_program
Why? In the first case, I want to run the program non-interactively, and in the latter case I want to print out user-friendly messages. I've been thinking along the lines of some check I haven't yet found, like:
Code:
if( stream_buffer_is_not_empty() )
print_interactive_messages();
If a process forks its child and communicate with the child using pipe, do closing the write end of the pipe and terminating the writing process have the same effect?
View 3 Replies View Relatedhow to pipe the current directory listing into sort so that the output is the date in descending order (primary sort key). If there are multiple entries with the same date, I'd like the times sorted in ascending order. It seems simple but for some reason this isn't working:
ls -l | sort -k 6r -k 7
For some reason it doesn't seem to ever get to the second sort key when using column 6 (last modified date).
I understand that the linux pipe is a buffer and that any data written to it will stay there until it is read, and if the max capacity of the buffer is reached, any additional writes will block (by default).
HOWEVER, the behavior of the pipeline below suggest that the write operations are buffered/cached before ever being written to the pipe on the client side here is write.sh, which creates 1000 byte string and writes it 100 times to stdout... the idea being that it'll block as soon as the 64kb linux pipe size is reached:
[Code]...
This is not what I was expecting: I was expected that once the capacity was reached, any reads would be followed immediately by a write to take advantage of the freed space. Instead, the blocked write operation seems to wait for some random amount of time/space to free until it unblocks and writes.
I am building a python script which works same as SMTP protocol. I have build separate functions in that for each command of SMTP, and after this i have integrated all those functions in a new function named as send_mail(so that i don't have to execute every function separately for every command). Now, when i execute the script for the first time it runs successfully, but for the second time it gives the error of "BROKEN PIPE". I really can't make out how the socket is getting closed.
View 5 Replies View RelatedI've written a usb device driver and a program that sends and receives data over the bulk pipe. The read function sometimes returnsI'm reading an unknown amount of data. However, using a usb tracker I can see that the correct data is being sent.The error only occurs sometimes.I expect that the read function is told to read more data that it receives it would fail and return -1, however if this was the case then every read call would fail.
View 4 Replies View RelatedMy question deals with me creating a name pipe (file) in the my /group directory called chat.I then have to write a script to read from the named pipe and save data into a file called chat.log until the words End of File are passed to the program.
-When I created the named pipe file (chat) I used the mknod chat p command..Is this the correct command to create a named pipe file? -Then I'm having trouble with my script and how to make it run until the words End of File are entered in. This is what I have so far.
I am not able to execute a multiple sed statement using pipe filters in a variable. i am trying to extract a path from a file and then working on that path to change a few letters within the path by going through another sed statement.
the code looks like this code...
I wrote y bash script that opens YouTube playlist using youtube-dl and VLC applications: the output of youtube-dl is the input of VLC. The only problem is VLC needs to be closed after each playlist item unless I get the error message of the operating system:
"ERROR: unable to write data: [Errno 32] Broken pipe".
I understand the reason but I don't know how to resolve it: it is possible to close previous STDIN of VLC without killing the entire VLC process so that a new youtube-dl instance can connect to the same VLC instance? In short this is my question. The problem is detailed here: Downloading and playing videos and subtitles.
