January 2004 - openSUSE Programming - openSUSE Mailing Lists

Set uid on executables
by Hallingstad Håkon 19 Jan '04

19 Jan '04

I have two programs that (for all practical purposes) should be identical. root@dirac:/tmp/ cat pids.c #include <stdlib.h> int main(int argc, const char *argv[]) { return system("/usr/bin/id"); } root@dirac:/tmp/ cat pids.sh #! /bin/bash /usr/bin/id root@dirac:/tmp/ ls -l pids* -rwsr-xr-x 1 root root 4814 Jan 18 23:16 pids -rw-rw-rw- 1 root root 95 Jan 18 23:16 pids.c -rwsr-xr-x 1 root root 25 Jan 19 09:38 pids.sh root@dirac:/tmp/ su - hakonhal hakonhal@dirac:~/ cd /tmp hakonhal@dirac:/tmp/ ./pids uid=1000(hakonhal) gid=1000(hakonhal) euid=0(root) groups=1000(hakonhal),24(cdrom),40(src),100(users) hakonhal@dirac:/tmp/ ./pids.sh uid=1000(hakonhal) gid=1000(hakonhal) groups=1000(hakonhal),24(cdrom),40(src),100(users) hakonhal@dirac:/tmp/ Why do not pids.sh also report euid=0? Does this mean setuid/setgid on bash scripts are useless and misleading? Regards, Håkon Hallingstad

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RE: [suse-programming-e] libpthread.so.0 not found trying to link simple app. Library is present in /lib
by Gustavo Dutra 15 Jan '04

15 Jan '04

Hi, It should work if you put -lpthread only. BTW, did you install pthread-dev(something like that) rpm??? -----Mensaje original----- De: Burt Bicksler [mailto:bbicksler@fortresstech.com] Enviado el: Thursday, January 15, 2004 4:10 PM Para: suse-programming-e(a)suse.com Asunto: [suse-programming-e] libpthread.so.0 not found trying to link simple app. Library is present in /lib Hi, I'm trying to build a simple hello world test application using pthreads. This is on a stock SUSE Pro 8.2 installation with all of the latest patches installed. During the link the linker whines that it cannot find libpthread.so.0. I have tried presenting this as -l/lib/libpthread.so.0 (which is where the lib physically resides). This doesn't change the problem, still no joy with linking the application. I'm probably doing something wrong, but I've scanned the web with Google and, while I've found similar problems with other libraries mentioned all of those appear to be related to not having the library installed. I haven't been able to track down a good specific example showing what library to link with, so I'm making the assumption that libpthread.so.0 is the correct one, but it doesn't appear to be recognized by the linker. Has anyone else encountered this problem, and if so what was the solution? If you can point me to a specific document that details the settings to use to build a "hello world" threaded application on SUSE 8.2 that would be great. Thanks, Burt --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com) Version: 6.0.558 / Virus Database: 350 - Release Date: 1/2/2004

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C++ compile problem. error in function
by ged.suse 14 Jan '04

14 Jan '04

Can anyone please, please show me what's going wrong here. (Full code listed at end of post) I'm trying to access a structure from within another structure but am receiving errors. Unfortunately, I need to build this on a windows machine, but I think I have made the code fully portable for Linux. It compiles with the mingw compiler anyway. Structures are global and are as follows: struct StockItem { int code; char desc[20]; float price; }stock[NUM_OF_ITEMS]; struct BillLine { StockItem stock; float weight; float cost; }bill_line[50]; The 'stock' array is already populated. All I'm trying to do is fill the 'BillLine bill_line' array in the first function, and then print out the array values in the second. My error seems to be coming from accessing one structure from another. My problem code is as follows, I've commented the line numbers flagged up by the compiler: BillLine bill_item(void) { BillLine bill; int item; cls(); cout << "Enter item number purchased: "; cin >> item; item -= 1; /*line 213*/ bill.stock = stock[item]; cout << "Weight: "; cin >> bill.weight; bill.cost = stock[item].price * bill.weight; return (bill); } void print_bill ( BillLine bill_line[50], int num_bill_items ) { for (int i=0; i<num_bill_items; ++i) { /*line 240*/ cout << "Name = " << bill_line[i].stock.desc << endl; cout << "Weight = " << bill_line[i].weight << endl; cout << "Cost = " << bill_line[i].cost << endl; } } MY compile log is as follows: Compiler: Default compiler Executing g++.exe... g++.exe "C:\Ged\code\assignment\best.cpp" -o "C:\Ged\code\assignment\best.exe" -g3 -O0 -g3 -I"C:\Ged\Dev-Cpp\include\c++" -I"C:\Ged\Dev-Cpp\include\c++\mingw32" -I"C:\Ged\Dev-Cpp\include\c++\backward" -I"C:\Ged\Dev-Cpp\include" -L"C:\Ged\Dev-Cpp\lib" C:/Ged/code/assignment/best.cpp: In function `BillLine bill_item()': C:/Ged/code/assignment/best.cpp:213: incompatible types in assignment of ` StockItem' to `StockItem[125]' C:/Ged/code/assignment/best.cpp: In function `void print_bill(BillLine*, int)': C:/Ged/code/assignment/best.cpp:240: request for member `desc' in `(bill_line + (+(i * 3508)))->BillLine::stock', which is of non-aggregate type ` StockItem[125]' Execution terminated The rest of the program runs fine. Although there is not much error checking (I'll add that later) there are no warnings when compiled. My full program code is as follows #include <iostream> #include <fstream> #include <conio.h> //for getch() using namespace std; const int NUM_OF_ITEMS = 125; struct StockItem { int code; char desc[20]; float price; }stock[NUM_OF_ITEMS]; struct BillLine { StockItem stock[NUM_OF_ITEMS]; float weight; float cost; }bill_line[50]; void cls(void) { system("cls"); } //function designed to aid portability. void disp_menu( void ); StockItem enter_data( void ); void delete_data( StockItem* ); void see_stock( StockItem*, int ); void writeToDisk( StockItem*, int ); int readFromDisk( StockItem* ); BillLine bill_item( void ); void print_bill ( BillLine*, int ); int main() { int ans, ctr; int num_stock_items = 0; int num_bill_items = 0; do { do { disp_menu(); cin >> ans; } while ((ans<1) || (ans>9)); switch (ans) { case 1: stock[num_stock_items] = enter_data(); num_stock_items++; break; case 2: delete_data( stock ); num_stock_items -= 1; break; case 3: see_stock(stock, num_stock_items); break; case 4: writeToDisk( stock, num_stock_items ); // NOT writing the whole array to disk. break; case 5: num_stock_items = readFromDisk( stock ); // setting the number items we read from file break; case 6: bill_line[num_bill_items] = bill_item(); num_bill_items++; break; case 7: print_bill( bill_line, num_bill_items ); break; default: break; } }while (ans!=8); return 0; } void disp_menu() { cout << "\n*** The Corner Shop ***\n\n"; cout << "Select an option: \n\n"; cout << "\t1. Enter new stock item " << endl; cout << "\t2. Delete stock item " << endl; cout << "\t3. See current stock " << endl; cout << "\t4. Save stock to disk " << endl; cout << "\t5. Load stock from disk " << endl; cout << "\t6. Enter purchase order " << endl; cout << "\t7. Print Bill " << endl; cout << "\t8. Exit \n" << endl; cout << "option> "; } StockItem enter_data(void) { StockItem stock_item; cls(); cout << "\n\nWhat is the product code: "; cin >> stock_item.code; cout << "What is the product description: "; cin.ignore(); cin.getline(stock_item.desc, 20); cout << "What is the product price: "; cin >> stock_item.price; cls(); return (stock_item); } void delete_data(StockItem stock[NUM_OF_ITEMS] ) { StockItem stock_temp[NUM_OF_ITEMS]; int item, n=0; cls(); cout << "Enter item to delete "; cin >> item; item -= 1; for(int i = 0; i < NUM_OF_ITEMS; i++) { if(i == item) ++n; stock_temp[i] = stock[n]; ++n; } for(int i = 0; i < NUM_OF_ITEMS; i++) stock[i] = stock_temp[i]; cls(); } void see_stock(StockItem stock[NUM_OF_ITEMS], int num_stock_items) { int ctr; cls(); cout << "\n\nHere is the stock listing:\n\n"; for (ctr = 0; ctr < num_stock_items; ++ctr) { cout << "Item " << ctr+1 << endl; cout << "Product Code: " << stock[ctr].code << endl; cout << "Product Description: " << stock[ctr].desc << endl; cout << "Price: " << stock[ctr].price << endl; cout << "------------------------------------------------\n"; } cout << "\nHit any key to continue.....\n"; getch(); cls(); } void writeToDisk( StockItem* array, int numOfItems ) { ofstream outfile( "items.txt" ); if (outfile.bad()) { cout << "\n*** Error opening file ***\n"; } for( int index = 0; index < numOfItems; index++ ) outfile.write( (char*)&array[index], sizeof(StockItem) ); cls(); } int readFromDisk( StockItem* array ) { int numOfItems = 0; ifstream infile( "items.txt" ); if (infile.bad()) { cout << "\n*** Error opening file ***\n"; } StockItem tmp_stockItem; // read from the file until we reach EOF while( infile.read( (char*)&tmp_stockItem, sizeof(tmp_stockItem) ) ) { // after a successfull read we store the the item into the array memcpy( &array[numOfItems], &tmp_stockItem, sizeof( array[numOfItems] ) ); numOfItems++; } cls(); // returning the number of array items we read from the file return numOfItems; } BillLine bill_item(void) { BillLine bill; int item; cls(); cout << "Enter item number purchased: "; cin >> item; item -= 1; bill.stock = stock[item]; cout << "Weight: "; cin >> bill.weight; bill.cost = stock[item].price * bill.weight; return (bill); } void print_bill ( BillLine bill_line[50], int num_bill_items ) { for (int i=0; i<num_bill_items; ++i) { cout << "Name = " << bill_line[i].stock.desc << endl; cout << "Weight = " << bill_line[i].weight << endl; cout << "Cost = " << bill_line[i].cost << endl; } }

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USB device
by expatriate 13 Jan '04

13 Jan '04

Hello I'm interested in some reading material on how to open/ioctl/read/write a /dev/usb/xxx device. Does anyone know of a good text/website? TIA & Cheers

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Please unsubscribe me from suse-programming-e@suse.com
by Twort, Richard 12 Jan '04

12 Jan '04

-----Original Message----- From: suse-programming-e-help(a)suse.com [mailto:suse-programming-e-help@suse.com] Sent: Wednesday, 2 July 2003 8:28 a.m. To: Twort, Richard Subject: confirm subscribe to suse-programming-e(a)suse.com Hi! This is the ezmlm program. I'm managing the suse-programming-e(a)suse.com mailing list. I'm working for my owner, who can be reached at suse-programming-e-owner(a)suse.com. To confirm that you would like richard.twort(a)openpolytechnic.ac.nz added to the suse-programming-e mailing list, please send an empty reply to this address: suse-programming-e-sc.1057091266.jpmliljoeajbalnfcgel-richard.twort=openpolytechnic.ac.nz(a)suse.com Usually, this happens when you just hit the "reply" button. If this does not work, simply copy the address and paste it into the "To:" field of a new message. or click here: mailto:suse-programming-e-sc.1057091266.jpmliljoeajbalnfcgel-richard.twort=openpolytechnic.ac.nz@suse.com This confirmation serves two purposes. First, it verifies that I am able to get mail through to you. Second, it protects you in case someone forges a subscription request in your name. --- Administrative commands for the suse-programming-e list --- I can handle administrative requests automatically. Please do not send them to the list address! Instead, send your message to the correct command address: For help and a description of available commands, send a message to: <suse-programming-e-help(a)suse.com> To subscribe to the list, send a message to: <suse-programming-e-subscribe(a)suse.com> To remove your address from the list, just send a message to the address in the ``List-Unsubscribe'' header of any list message. If you haven't changed addresses since subscribing, you can also send a message to: <suse-programming-e-unsubscribe(a)suse.com> For addition or removal of addresses, I'll send a confirmation message to that address. When you receive it, simply reply to it to complete the transaction. If you need to get in touch with the human owner of this list, please send a message to: <suse-programming-e-owner(a)suse.com> Please include a FORWARDED list message with ALL HEADERS intact to make it easier to help you. --- Enclosed is a copy of the request I received. Return-Path: <richard.twort(a)openpolytechnic.ac.nz> Received: (qmail 3939 invoked from network); 1 Jul 2003 20:27:45 -0000 Received: from ns.suse.de (HELO Cantor.suse.de) (213.95.15.193) by 0 with SMTP; 1 Jul 2003 20:27:45 -0000 Received: from Hermes.suse.de (Hermes.suse.de [213.95.15.136]) by Cantor.suse.de (Postfix) with ESMTP id 00F35150C5 for <suse-programming-e-subscribe(a)lists.suse.com>; Tue, 1 Jul 2003 22:27:44 +0200 (MEST) Received: from Cantor.suse.de (ns.suse.de [213.95.15.193]) by Hermes.suse.de (Postfix) with ESMTP id EFDE01104 for <suse-programming-e-subscribe(a)suse.com>; Tue, 1 Jul 2003 22:27:44 +0200 (CEST) Received: from turing.suse.de (Turing.suse.de [213.95.15.200]) by Cantor.suse.de (Postfix) with ESMTP id E7002150C5 for <suse-programming-e-subscribe(a)suse.com>; Tue, 1 Jul 2003 22:27:44 +0200 (MEST) Date: Tue, 1 Jul 2003 22:27:44 +0200 From: richard.twort(a)openpolytechnic.ac.nz Message-Id: <200307012027.h61KRik29102(a)turing.suse.de> To: undisclosed-recipients: ;

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(C++) Saving / reading structures to / from disk (desperate measures)
by ged.suse＠ntlworld.com 08 Jan '04

08 Jan '04

Thanks to all who have helped so far :) I don't have much time left to get this program running, so I have opted to drop the functions and try and get it running in the main()..... ....however, I still can't get it to do what I want. Can anyone PLEASE help me with this. I would be very grateful, I need to get this program running. Cade now as follows: #include <iostream> #include <fstream> using namespace std; struct StockItem { int code; char desc[20]; float price; }stock[125]; /*struct bill_line { StockItem product; float weight; float cost; }; struct bill { bill_line items[20]; int num_lines; };*/ void disp_menu(void); struct StockItem enter_data(); void see_stock(StockItem stock[125], int num_items); main() { int ans, ctr; int num_items = 0; FILE *item_file = NULL; do { do { disp_menu(); cin >> ans; } while ((ans<1) || (ans>6)); switch (ans) { case 1: stock[num_items] = enter_data(); num_items++; break; case 2: see_stock(stock, num_items); break; case 3: { item_file = fopen("items.txt", "ab"); for (ctr=0;ctr<125;++ctr) { fwrite(&stock[ctr], sizeof(StockItem), 3, item_file); } fclose(item_file); break; } case 4: { item_file = fopen("items.txt", "rb"); for (ctr=0;ctr<125;++ctr) { fread(&stock[ctr], sizeof(StockItem), 3, item_file); } fclose(item_file); break; } default: break; } }while (ans!=5); return 0; system("PAUSE"); return 0; } void disp_menu() { cout << "\n*** The Corner Shop ***\n\n"; cout << "Select an option: \n\n"; cout << "\t1. Enter new stock " << endl; cout << "\t2. See current stock " << endl; cout << "\t3. Save stock to disk " << endl; cout << "\t4. Load stock from disk " << endl; cout << "\t5. Exit \n" << endl; cout << "option> "; } StockItem enter_data() { StockItem stock_item; cout << "\n\nWhat is the product code: "; cin >> stock_item.code; cout << "What is the product description: "; fflush(stdin); cin.getline(stock_item.desc, 20); cout << "What is the product price: "; cin >> stock_item.price; return (stock_item); } void see_stock(StockItem stock[125], int num_items) { int ctr; char ret; cout << "\n\nHere is the stock listing:\n\n"; for (ctr = 0; ctr < num_items; ++ctr) { cout << "Item " << ctr+1 << endl; cout << "Product Code: " << stock[ctr].code << endl; cout << "Product Description: " << stock[ctr].desc << endl; cout << "Price: " << stock[ctr].price << endl; cout << "------------------------------------------------\n"; } } > > From: Salman Khilji <skhilji(a)tampabay.rr.com> > Date: 2004/01/06 Tue AM 06:32:27 GMT > To: ged.suse(a)ntlworld.com > Subject: Re: [suse-programming-e] (C++) Saving / reading structures to / from disk > > Sorry I don't have time to give you a complete implementation, but lets see > what I can pull out of my brain. the following won't compile, but will give > you a brief idea as how to read and write a structure to/from disk. The > following will NOT work with structure that have embedded pointers in them. > > > example: > > struct Foo { > float bar; > int john; > }; > > Foo array[2]; > > ... populate the array of structs... > > FILE * file = fopen("myfile", "w+b"); > fwrite(file, array, sizeof(array)); // I know the arguments are wrong here, > but lookup the docs to correct it. > > > To read it back, first use fopen call and read it into a char array. > > Then do this. > > Foo * array; > > array = (Foo*) myCharArray; > > After this, you should be able to see what the contents of Foo are. > > > I have an example that does this, but its at my office and I will have to dig > it out. > > Salman > > ----------------------------------------- Email provided by http://www.ntlhome.com/

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Re: [suse-programming-e] Tips for PCRE expressions?
by Mark Gray 08 Jan '04

08 Jan '04

Trey Gruel <drathos-suse(a)nightmoose.net> writes: >> Secondly, it is almost always a mistake to try to do all your work >> using a single regex -- use multiple regex's and program logic based >> on the results. > One of the reasons I'm trying to move things to regex is so the simpler > checks can be edited in config files that can be reloaded on the fly. Have you considered embedding a perl interpreter in your program? Not such overkill if you have a lot of configuration that you would like to be that flexible. (For one regex, it would be overkill though:-) > If this check ends up being a problem, I may end up making an option for a > "negative check" where it'll match invalid values. Prolly not a bad idea > anyway.. This is what the perl cookbook 2nd edition (page 61) gives for a VALID C float: ^([+-]?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$ and pcretest seems to like it: markgray@soyo:/ARK/BOOKS/perlcookbook2/ch02> pcretest PCRE version 4.4 21-August-2003 re> /^([+-]?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$/ data> 123.45 0: 123.45 1: 2: .45 data> -123.45 0: -123.45 1: - 2: .45 data> unkn No match data> NaN No match data> abcdef No match data> +123.456e+02 0: +123.456e+02 1: + 2: .456 3: e+02 4: +02 data>

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Re: [suse-programming-e] Tips for PCRE expressions?
by Mark Gray 08 Jan '04

08 Jan '04

Trey Gruel <drathos-suse(a)nightmoose.net> writes: > I'm trying to implement some data checking using PCRE for regular > expressions. My experience using regex is fairly limited and very > rusty. For the most part, I've been able to replace most of the > simple C based checks with regex, but I'm having trouble with one > that I think should be possible with regex. > What I'm having trouble with is a check of an alphanumeric field (up > to 10 characters) that lets everything *except* UNK, UNKN, and > UNKNOWN through (logic being if it's unknown, it should be blank). > I was thinking I should be able to do this with look-ahead or > look-behind assertion, but I can't seem to make it work. > Any ideas would be appreciated. First off, get ahold of a copy of: Mastering Regular Expressions, 2nd Edition By Jeffrey E. F. Friedl 2nd Edition July 2002 ISBN 0-596-00289-0, Order Number: 2890 484 pages, $39.95 US, $61.95 CA, 28.50 UK O'Reilly Secondly, it is almost always a mistake to try to do all your work using a single regex -- use multiple regex's and program logic based on the results.

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Tips for PCRE expressions?
by Trey Gruel 07 Jan '04

07 Jan '04

I'm trying to implement some data checking using PCRE for regular expressions. My experience using regex is fairly limited and very rusty. For the most part, I've been able to replace most of the simple C based checks with regex, but I'm having trouble with one that I think should be possible with regex. What I'm having trouble with is a check of an alphanumeric field (up to 10 characters) that lets everything *except* UNK, UNKN, and UNKNOWN through (logic being if it's unknown, it should be blank). I was thinking I should be able to do this with look-ahead or look-behind assertion, but I can't seem to make it work. Any ideas would be appreciated. -- trey

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Re: (forw) [suse-programming-e] SuSE-9.0 /usr/include/wx/html/htmlproc.h left out of wxGTK-devel package
by Michal Čihař 07 Jan '04

07 Jan '04

Hi > ----- Forwarded message from Mark Gray <markgray-temp-1072781312(a)iago.nac.net> ----- > While this might not be > the only bug in wxGTK-devel (I am still working my way through the > samples) /usr/include/wx/html/htmlproc.h is not packaged up to be > installed in the wxGTK-devel package (which causes html/test/test.cpp > to fail to compile) Copying htmlproc.h from the source package to > /usr/include/wx/html/ fixes the problem. Well this is bug in wxWindows install scripts (they have there manually maintained list of files to install). I reported it to their bugs (bug #872377). I'll make some more checks what other headers are not installed before next release. -- Best Regards, Michal Cihar SUSE CR, s.r.o.

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