Programming :: C Syntax - Passing In Unknown Number Of Arguments?
May 18, 2009
I need to write a wrapper function around the mvprintw function, like so:
int smvprintw( ? )
{
// Do various checks/modifications on the first two arguments (int y,
int x) first,
// and then
return mvprintw ( ? );
}
How should I write the args for smvprintw so that I can pass all the data correctly to mvprintw, and also do my checks on the first two args (for example, to modify them)? I'm confused by the prototype of mvprintw: This is mvprintw as listed in the man pages:
I believe the "..." refers to the unknown number of items after const char * fmt. Will it suffice to do something like "int smvprintw(int y, int x, const char * fmt, void * etc)" and then "mvprintw(y, x, fmt, etc)" inside the function?
I want to write a little time-saving alias for my .cshrc file that will move files and then cd to the directory I've moved them to. What I can't quite figure out is the syntax to say 'move all the arguments except the last one.' Here is what I have:
alias follow 'mv !:1-$-1 !:$; cd !:$'
This actually seems to work, but it also gives me an irritating error:
mv: cannot stat `destinationdirectory/-1': No such file or directory
Similarly, I tried:
alias follow 'mv !:*$#argv-1 !:$; cd !:$'
Again the move and cd are successful, but again there is an error:
mv: cannot stat `destinationdirectory/0-1': No such file or directory
what I am trying to do is to pass an argument to the standard input stream of a child process. I mean I create two programs .. first one invokes the other. second one contains something like
Code:
scanf("%d", &n);
now I want my first program to be able to pass a value to the second one so that it gets stored in n.
I am calling another executable in my application (C programing) using "system" command which is user interactive program. now i want to pass those args in system command only.
system(" executable ");
Executable will expect 1,2 or 3.
1 is to continue 2 for do changes in settings 3 exit from application
As you can see, I want to pass arguments depending on the option(s) chosen by the user; ie. --snooze, or --channel. By default, if no options are chosen, I'll display a usage message; though in the future I'll provide some sane defaults. I'd like to create a case statement to handle passing arguments to any number of options; something like:
Code:
wakethehellup.sh --snooze 20 --message 'wake up!'
and for the other arguments, it would have a default set. The case statement I provided fails with a syntax error "syntax error near unexpected token `$2'" near the '--snooze' in the statement, so I take it you can't pass a parameter in this way; but I'm confused as to how I'm supposed to pass different parameters to different options without the options being confused as parameters.
how to use QGLviewer. I want to give my program a file name as a command line argument. All of the sample programs I find have a main.cpp file like this:
Quote:
#include <QApplication> #include "window.h" int main(int argc, char *argv[])
[code]....
Then the Window class, which is derived from QGLViewer, does all the program's actual work. If I want access to argc and argv, for example, to open and read a file that's passed as an argument, what would handle that? Is there a built-in way to get the arg variables to the window class, or do I need to just write a loadfile function and pass them?
I'm using gdb to debug my program. My program requires arguments (e.g., ./prog -dfile).But if I use gdb as in gdb ./prog -dfile, gdb wants to interpret the -d argument. How do I pass an argument to my program via gdb?
It seems incrontab wont see spaces properly at all. I setup a script to echo the arguments passed to it by incrontab to a file, and no matter what I put around the arguments on the incrontab file it will count a space as the next argument.
I have written a script to automatically retrieve imdb artwork for a given filename. Here is the script:
Code:
You can ignore all the commented "echo" commands that was just me testing. Anyway, the script work fine, however I am trying to use incrontab to monitor a folder, when a new (video) file is moved into the folder, it should execute the script and retrieve the artwork. My problem is, when incrontab passes the $# argument to my script, the script wont work because the spaces aren't escaped.
Here is some more detail:
Incrontab
Code:
Code:
The problem is, the script GetArtwork, doesn't see "Bangcock Dangerous" it just sees "Bangcock"
I have tried putting quotes around the $# in the incrontab - this just makes the script see "Bangcock (notice the single quote character)
The script receives multiple files as parameters and it is supposed to count the number of lines in each of them and write that number in another file.
This is my script:
Code:
while [ -n "$1" ] do lines=`cat $1 | wc -l` echo "The number of lines in file $1 is $lines." >> lines.txt shift done
Is there any other way to do the same thing, without using shift?
Problem: I need a method to maintain the $i variable. In fact, actually, this variable get lost when executed. I think that an escape can preserve this variable and permit its execution inside the function, but I've no idea about.
I wrote a simple bash script to let me treat any set of programs like a deamon. For example if I configure the script a certain way I can start/stop/get the status of apache, mysql and php all from one command. I am having a bit of a problem though. I am passing commands as strings to a function and then depending on the arguments to the script it might run one of these commands or another. Some of these commands need to beun in the background though, such as deluge-web. When I send "deluge-web &" to the function and it execute it deluge-web does not start in the background. I can't figure out why this is. I have tried escaping the & with ''s and with a , but nothing seems to work. I know that this is some idiotic thing that I am overlooking, but I am a bit stumped. Here is the script configured to start/stop/get status of deluged and deluge-web.
I'm at the bottom of the bash learning curve, looking up, hoping someone can toss me a line. I need to update tracker on my system but this will erase the metatag database I've been building up over the course of months for the purpose of indexing a news archive. So the solution seems to be, 1) save the output of tracker-tag to a text file for all relevant files within a directory, 2) upgrade tracker (since the version in the Ubuntu repositories is very much out of date) and then 3) use a script to parse the text file and pass appropriate arguments back to tracker-tag to rebuild the database. It sounds as though it ought to be simple enough, but I need a push in the right direction, which hopefully will not be off the cliff. Before I confuse my metaphors any further, here's what the text file looks like.
I just upgraded from jaunty and somewhere in the process (or just after, I'm no longer sure just when it started) I started getting this error whenever I try to install or upgrade a package. Some of my software isn't working properly - some won't even load - so I'm not sure if the installations are actually succeeding, or not. But apt-get install -f shows nothing but a list of stuff I need to autoremove (mostly dev files). This particular message is the output of the details tab in synaptic, but I've gotten the same thing in terminal from apt-get. Quote:
dpkg-deb: --control /var/cache/apt/archives/dpkg-awk_1.0.3_all.deb /var/lib/dpkg/tmp.ci Selecting previously deselected package dpkg-awk. (Reading database ... 415515 files and directories currently installed.)
I just installed my Lubuntu, but I upgrade to lubuntu 11.04 (natty), after that I decided to try unity, so I installed ubuntu-desktop and unity, but when I try to start session on Ubuntu or unity it told me the title error, then I got the error.It open me a session without any menues and just a clean desktop.On another topic, after I upgrade, Lubuntu ask the password each time I turn on my computer, But when I try to change the settings and click on the button that say: enter session without asking password, that button appear locked.How do I unlock it?
I'm trying to use sed to search for a certain 'primary' pattern that may exist on several lines, with each primary pattern followed by an --unknown-- number of 'secondary' patterns.The lines containing the pattern start with: test(header_name)On that same line is an arbitrary number of strings that come after it.I want to move those strings over to their own lines so that they each are preceded by their own test(header_name).e.g. Original file (mytest.txt):
apples test("Type1", "hat", "cat", "dog", "house"); bananas
we use for the installation of our machines bladelogic. We have different servers. Some servers have only one network interface, but it can be 2, 4 or may be more. There is always one network device for using PXE, but it is not always eth0.Is there any way to run kickstart without the entering of the PXE-Device so, that kickstart checks all the network devices in the system?
I wrote a C program using Pthreads to compute the product of 2 matrices. Each element in the product matrix is computed in a separate thread. Eg: Thread (i,j) computes the element C[i][j] of the matrix C, where C=A*B. A is m*n, B is n*p, C is m*p. m,n,p are given as command-line arguments. A and B are initialized to random values from 1 to 10, while all elements of C are initialized to -1.But some threads do not get their arguments (i,j) correctly. So some elements C[i][j] still remain as -1, even after the program is over. My OS is Ubuntu 10.10 (Maverick Meerkat) 32-bit.I ran the program on another computer and it worked correctly. Is it due to a problem in the Pthreads library in my OS? Please help me. I have attached the source code.
I've been reading about getopt and getopts but it doesn't seem like it's possible to parse arguments like --foo or even -foo. I've started my own script trying to achieve this, but I'm still wondering if I'm losing performance and if there is a better way to do this task.
Also I'm using the [[ =~ ]] regex syntax which seems to be available only in newer bash versions, should it be a big issue? My bash version: GNU bash, version 4.1.7(2)-release (x86_64-unknown-linux-gnu)
I'm trying to compile the hidtouch driver, but hit a snag. The error I get is
[code]....
Context: this is the driver for the touchscreen attached to an LTSP client. The server uses the AMD64 arch, the client uses the 1386 arch, both Debian. The client does start, but lacking a pointer device the pointer is useless. The build takes place on the server, in the i386 chroot of the LTSP setup. Basically, I'm stuck now...
In the above example, the functions take no input arguments. Can they take a different number of arguments, for example, function_a(int), function_c(int, int), function_e(int, char, int)? How can I do that?
