•
•
•
•
What is DaniWeb IT Discussion Community?
You're currently browsing the C++ section within the Software Development category of DaniWeb, a massive community of 374,011 software developers, web developers, Internet marketers, and tech gurus who are all enthusiastic about making contacts, networking, and learning from each other. In fact, there are 2,812 IT professionals currently interacting right now! Registration is free, only takes a minute and lets you enjoy all of the interactive features of the site.
Please support our C++ advertiser:
Views: 218 | Replies: 8
 |
•
•
Join Date: May 2008
Posts: 4
Reputation: 
Rep Power: 0
Solved Threads: 0
Newbie Poster
Hi,
I'm very new to C++ and was wondering how I would go about searching for a string (AT+COPS?) in a file and displaying everything to the right of the string, could someone point me in the direction of a guide
cheers
I'm very new to C++ and was wondering how I would go about searching for a string (AT+COPS?) in a file and displaying everything to the right of the string, could someone point me in the direction of a guide
cheers
•
•
Join Date: May 2006
Location: ★★ijug.net★★
Posts: 817
Reputation:
Rep Power: 4
Solved Threads: 61
Practically a Posting Shark
Open the file read it line by line as a string and then use a string api to search for the keyword. It is quite cumbersome homework I would say.
★★ Homework Help ★★ Freelance Programmer ★★ Freelance Jobs ★★
★★ Build A Website ★★ Interview Question And Answer ★★ Tax Filing ★★
★★ Build A Website ★★ Interview Question And Answer ★★ Tax Filing ★★
•
•
Join Date: May 2008
Posts: 274
Reputation:
Rep Power: 2
Solved Threads: 46
Posting Whiz in Training
The hardest part is opening the file, then it's just like reading input from cin:
#include <fstream>
#include <iostream>
#include <string>
int main()
{
std::ifstream is("myfile");
std::string line;
while (std::getline(is, line)) {
std::string::size_type start = line.find("AT+COPS");
if (start != std::string::npos)
std::cout << line.substr(start) << '\n';
}
} Subtlety is the art of saying what you think and getting out of the way before it is understood.
•
•
Join Date: May 2008
Posts: 4
Reputation:
Rep Power: 0
Solved Threads: 0
Newbie Poster
•
•
•
•
Originally Posted by Radical Edward 
The hardest part is opening the file, then it's just like reading input from cin:
#include <fstream> #include <iostream> #include <string> int main() { std::ifstream is("myfile"); std::string line; while (std::getline(is, line)) { std::string::size_type start = line.find("AT+COPS"); if (start != std::string::npos) std::cout << line.substr(start) << '\n'; } }
to assignt the output to a varaible would I do something like
String copsoutput;
copsoutput = line.substr(start);
I'm more of a visual baic & c# man, and wish my project would let write it in VB or C#
cheers
•
•
Join Date: Aug 2005
Location: near St Louis, Missouri, USA
Posts: 10,182
Reputation: 
Rep Power: 34
Solved Threads: 822
>> I'm more of a visual baic & c# man, and wish my project would let write it in VB or C#
This is c++ board. If you want vb or c# then ask your question there.
>>String copsoutput;
That needs to be lower-case s on string
>>to assignt the output to a varaible would I do something like
Yes -- you got the idea
This is c++ board. If you want vb or c# then ask your question there.
>>String copsoutput;
That needs to be lower-case s on string
string copsoutput;
>>to assignt the output to a varaible would I do something like
Yes -- you got the idea
Last edited by Ancient Dragon : May 19th, 2008 at 12:08 pm.
'Politics' is made up of two words, 'poli,' which is Greek for 'many,' and 'tics,' which are blood-sucking insects.
- Gore Vidal
Being ignorant is not so much a shame as being unwilling to learn. - Benjamin Franklin
- Gore Vidal
Being ignorant is not so much a shame as being unwilling to learn. - Benjamin Franklin
•
•
Join Date: May 2008
Posts: 4
Reputation:
Rep Power: 0
Solved Threads: 0
Newbie Poster
lucky I'm trying to write a c++ program then 
anyhow when i try to complie the app using
I receive the following error:
cannot convert std::string to const void for argument 2 to ssize_t write(int, const void*, size_t)
anyhow when i try to complie the app using
while (std::getline(is, line))
{
std::string::size_type start = line.find("+COPS:");
if (start != std::string::npos)
write(lcd,secondrow,sizeof(secondrow));
copsoutput = line.substr(start);
write(lcd,copsoutput,sizeof(copsoutput));
}I receive the following error:
cannot convert std::string to const void for argument 2 to ssize_t write(int, const void*, size_t)
Last edited by uk101man : May 19th, 2008 at 12:28 pm.
•
•
Join Date: Aug 2005
Location: near St Louis, Missouri, USA
Posts: 10,182
Reputation:
Rep Power: 34
Solved Threads: 822
>>cannot convert std::string to const void for argument 2 to ssize_t write(int, const void*, size_t)
the function write is wanting a pointer as the second parameter and you are passing std::string. The third parameter is also wrong. try this:
the function write is wanting a pointer as the second parameter and you are passing std::string. The third parameter is also wrong. try this:
write(lcd,copsoutput.c_str(), copsoutput.length()); Last edited by Ancient Dragon : May 19th, 2008 at 12:37 pm.
'Politics' is made up of two words, 'poli,' which is Greek for 'many,' and 'tics,' which are blood-sucking insects.
- Gore Vidal
Being ignorant is not so much a shame as being unwilling to learn. - Benjamin Franklin
- Gore Vidal
Being ignorant is not so much a shame as being unwilling to learn. - Benjamin Franklin
•
•
Join Date: May 2008
Posts: 4
Reputation:
Rep Power: 0
Solved Threads: 0
Newbie Poster
now the app compiles but when I run it I thrown out with
terminate called after throwing an instance of 'std::out_of_range' what(): basic_string::substr Aborted
•
•
Join Date: Aug 2005
Location: near St Louis, Missouri, USA
Posts: 10,182
Reputation:
Rep Power: 34
Solved Threads: 822
what is secondrow ?
while (std::getline(is, line))
{
std::string::size_type start = line.find("+COPS:");
if (start != std::string::npos)
{
write(lcd,secondrow,sizeof(secondrow));
copsoutput = line.substr(start);
write(lcd,copsoutput.c_str(), copsoutput.length());
}
} Last edited by Ancient Dragon : May 19th, 2008 at 1:12 pm.
'Politics' is made up of two words, 'poli,' which is Greek for 'many,' and 'tics,' which are blood-sucking insects.
- Gore Vidal
Being ignorant is not so much a shame as being unwilling to learn. - Benjamin Franklin
- Gore Vidal
Being ignorant is not so much a shame as being unwilling to learn. - Benjamin Franklin
|
•
•
•
•
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
•
•
•
•
•
•
•
•
DaniWeb C++ Marketplace
Linear Mode
•
•
•
•
adsense adult advertising biometrics blogging book business coding community copyright cult of the dead cow data development earth engine europe forum google hacking image recognition internet search legal malware marketing mcafee microsoft monetization msn news pagerank photo privacy publishing ratings revenue search search engine security seo sex software spyware support technical video video search web webmaster wiki yahoo
- C File handling - search within file without reading content? (C++)
- Replacing text within a file using awk (Shell Scripting)
- Searching a file for a string (C++)
- problem with incrementing numbers in a file (Perl)
- My Way Search Assistant (ive run all the scans already) (Viruses, Spyware and other Nasties)
- String search in a file compare? (Computer Science and Software Design)
Other Threads in the C++ Forum
- Previous Thread: How to restrict memory usage of a c++ program
- Next Thread: Order Tracking sytem. Please help assp. I have no idea how to do!!!!!!!!!!!!!!!!!!
