Ryan Tomayko touched off quite a fire storm with this post about using Unix process control commands. We should be doing more of this. A lot more of this. I'm talking about fork(2), execve(2), pipe(2), socketpair(2), select(2), kill(2), sigaction(2), and so on and so forth. These are our friends. They want so badly just to help us. ...
I've done some research and I'm still struggling with the passwd structure. http://www.opengroup.org/onlinepubs/000095399/basedefs/pwd.h.html I need to obtain the user ID however I dont think I'm using understanding it at all. int getpwuid_r(uid_t, struct passwd *, char *, size_t, struct passwd **); This method call returns a point t...
I'm trying to start doing Android development on OS X (trying is the key here). I've read all the fun stuff at http://developer.android.com/sdk/index.html. I get the basics, install the JDK, Eclipse, the Android SDK, the Eclipse plugin and ADT. That's a lot to do but I get the point of each step, so, OK, fine. Then there are a millio...
I am looking to buy a book on UNIX for programming, shell scripts and overall about UNIX, any useful UNIX tutorial websites or books you guys recommend? ...
I'll write a program for Interactive UNIX (http://en.wikipedia.org/wiki/INTERACTIVE%5FUNIX). But in a year it will be ported to Windows. I'll write it in ANSI C and/or SH-script. When it runs on Windows it will be run as a Windows service. How do I make it as easy as possible for me? I want to change as little as possible when I port it...
I have the old 8book O'Reily Serious "The X Resources" in my bookshelf bought about 15 years ago. Is there any book which is explaining the new technologies and X11 extensions like XDnD, Xinerama, XCursor, XRandR, XRender, XIM + Input Methods etc. maybe with a chapter (but not more) of GTK and QT. I'm not even asking for Compiz and ot...
Hello All... I am developing an application where i required to run some of the scripts of unix from Java Code. Platform i am using is Unix, Tomcat 5.5.. For that, My Sample Code is as follows : Runtime runtime = Runtime.getRuntime(); Process proc = runtime.exec("netstat -i|tail -n +3|cut -d ' ' -f1"); System.out.println("exitValue =...
i have a unix c programming assignment in which i do some advanced C network programming.this is my first step into advance programming. so i was wondering what is the best combination of tools for this on a mac. using an IDE like Eclipse is how i'd normally do it but i have to make my own makefiles and stuff. so i would like to learn ho...
What is the meaning of return value 127 from $? in UNIX. ...
Dear Stackoverflow, Once upon a time, a team of guys sat down and wrote an application in C, running on VMS on a VAX. It was a rather important undertaking and runs a reasonably important back-end operation at LargeCo. This whole shebang works so well that twenty-five years later it's still chugging along and doing it's thing. Time pa...
Hi, I use code in !/bin/sh like this: LIST1="mazda toyota honda" LIST2="2009 2006 2010" for m in $LIST1 do echo $m done As you can see this currently prints out only the make of the car. How can I include the year to each "echo" based on the same positions so that I get results like: mazda 2009 toyota 2006 honda 2010 ? ...
When I pass in 2009 as a arg to this shell function it returns 0, why? isyear() { case $arg in [0-9][0-9][0-9][0-9]) NUM=1 ;; *) NUM=0 ;; esac echo $arg } ...
Hi All, What would be the best approach to process a call like this to my shell script? ./cars Mazda Toyota 2010 Honda BMW VW 2009 So that it prints out: Mazda 2010 Toyota 2010 Honda 2009 BMW 2009 VW 2009 I can't use arrays because it's the most simple version of shell so it doesn't support them. Any ideas? ...
Hi all, I'm trying to detect whether a string holds a dash but nothing seems to work for me (I'm new to shell). if [ "$m" -eq "-" ] then echo "has dash" else echo "has no dash" fi ...
Hi, I'm completely new to shell and I'm trying to include a case where the function's arg #1 is greater or equal 12 then it should return 1. But the below doesn't work. case $1 in -ge 12) NUM=1 ;; *) NUM=0 ;; esac echo $NUM ...
Hi All, I'm writing a program where at some point in my loop I want to print to output whatever is stored in a separate file (an image). But if I code it like this: for c in $LIST do clear ./image.0 done And the "image.0" file contains only an image like this: +----+ | | | | | | | ======== Then when I run my program I ...
Hi All, I use the below code to assign a given by the user character to variable G: read G However in order to move forward with executing of my script I need to press enter button. Is it possible to set the read command somehow that it show process forward to the next line immediately after it receive the one letter from stdin? ...
Hi, I have a function which I use in my shell script and based on a certain condition I'd like to call "exit 0" in that function so that the entire script exits. But for some reason the program still runs after calling exit 0 in the function. Why? check() { printf "Would you like to try again?\n" read S if [ "$S" = "y" ] then ...
Hi I coded the below code and if no -l or -L option is passes to the script I need to assume (detect) whether a filename was passed as a param. The below third condition only matches if filename is one lowercase character. How can I make it flexible to match upper and lower case letters or variable length of the string? while [ $# -gt...
I have data file that stores records like this: make=honda|model=civic|color=red make=toyota|model=corolla|color=blue What would be the best way to detect (based on the make field) whether a given make exists in the file and then replace it with a new record? (Using shell script) ...