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I'm trying to parse an INI file using C++. Any tips on what is the best way to achieve this? Should I use the Windows API tools for INI file processing (with which I am totally unfamiliar), an open-source solution or attempt to parse it manually?
You can use the Windows API functions, such as GetPrivateProfileString() and GetPrivateProfileInt().
If you need a cross-platform solution, try Boost's Program Options library.
I have never parsed ini files, so I can't be too specific on this issue.
But i have one advice:
Don't reinvent the wheel as long as an existing one meets your requirements
http://en.wikipedia.org/wiki/INI_file#Accessing_INI_files
http://sdl-cfg.sourceforge.net/
http://sourceforge.net/projects/libini/
http://www.codeproject.com/KB/files/config-file-parser.aspx
Good luck :)
If you are already using Qt
QSettings my_settings("filename.ini", QSettings::IniFormat);
Then read a value
my_settings.value("GroupName/ValueName", <<DEFAULT_VAL>>).toInt()
There are a bunch of other converter that convert your INI values into both standard types and Qt types. See Qt documentation on QSettings for more information.
I use SimpleIni. It's cross-platform.
this question is a bit old, but I will post my answer. I have tested various INI classes (you can see them on my website) and I also use simpleIni because I want to work with INI files on both windows and winCE.
Window's GetPrivateProfileString() works only with the registry on winCE.
It is very easy to read with simpleIni. Here is an example:
#include "SimpleIni\SimpleIni.h"
CSimpleIniA ini;
ini.SetUnicode();
ini.LoadFile(FileName);
const char * pVal = ini.GetValue(section, entry, DefaultStr);
inih is a simple ini parser written in C, it comes with a C++ wrapper too. Example usage:
#include "INIReader.h"
INIReader reader("test.ini");
std::cout << "version="
<< reader.GetInteger("protocol", "version", -1) << ", name="
<< reader.Get("user", "name", "UNKNOWN") << ", active="
<< reader.GetBoolean("user", "active", true) << "\n";
The author has also a list of existing libraries here.
Have you tried libconfig; very JSON-like syntax. I prefer it over XML configuration files.
I ended up using inipp which is not mentioned in this thread.
https://github.com/mcmtroffaes/inipp
Was a MIT licensed header only implementation which was simple enough to add to a project and 4 lines to use.
If you are interested in platform portability, you can also try Boost.PropertyTree. It supports ini as persistancy format, though the property tree my be 1 level deep only.
Unless you plan on making the app cross-platform, using the Windows API calls would be the best way to go. Just ignore the note in the API documentation about being provided only for 16-bit app compatibility.
I know this question is very old, but I came upon it because I needed something cross platform for linux, win32... I wrote the function below, it is a single function that can parse INI files, hopefully others will find it useful.
rules & caveats:
buf to parse must be a NULL terminated string. Load your ini file into a char array string and call this function to parse it.
section names must have [] brackets around them, such as this [MySection], also values and sections must begin on a line without leading spaces. It will parse files with Windows \r\n or with Linux \n line endings. Comments should use # or // and begin at the top of the file, no comments should be mixed with INI entry data. Quotes and ticks are trimmed from both ends of the return string. Spaces are only trimmed if they are outside of the quote. Strings are not required to have quotes, and whitespaces are trimmed if quotes are missing. You can also extract numbers or other data, for example if you have a float just perform a atof(ret) on the ret buffer.
// -----note: no escape is nessesary for inner quotes or ticks-----
// -----------------------------example----------------------------
// [Entry2]
// Alignment = 1
// LightLvl=128
// Library = 5555
// StrValA = Inner "quoted" or 'quoted' strings are ok to use
// StrValB = "This a "quoted" or 'quoted' String Value"
// StrValC = 'This a "tick" or 'tick' String Value'
// StrValD = "Missing quote at end will still work
// StrValE = This is another "quote" example
// StrValF = " Spaces inside the quote are preserved "
// StrValG = This works too and spaces are trimmed away
// StrValH =
// ----------------------------------------------------------------
//12oClocker super lean and mean INI file parser (with section support)
//set section to 0 to disable section support
//returns TRUE if we were able to extract a string into ret value
//NextSection is a char* pointer, will be set to zero if no next section is found
//will be set to pointer of next section if it was found.
//use it like this... char* NextSection = 0; GrabIniValue(X,X,X,X,X,&NextSection);
//buf is data to parse, ret is the user supplied return buffer
BOOL GrabIniValue(char* buf, const char* section, const char* valname, char* ret, int retbuflen, char** NextSection)
{
if(!buf){*ret=0; return FALSE;}
char* s = buf; //search starts at "s" pointer
char* e = 0; //end of section pointer
//find section
if(section)
{
int L = strlen(section);
SearchAgain1:
s = strstr(s,section); if(!s){*ret=0; return FALSE;} //find section
if(s > buf && (*(s-1))!='\n'){s+=L; goto SearchAgain1;} //section must be at begining of a line!
s+=L; //found section, skip past section name
while(*s!='\n'){s++;} s++; //spin until next line, s is now begining of section data
e = strstr(s,"\n["); //find begining of next section or end of file
if(e){*e=0;} //if we found begining of next section, null the \n so we don't search past section
if(NextSection) //user passed in a NextSection pointer
{ if(e){*NextSection=(e+1);}else{*NextSection=0;} } //set pointer to next section
}
//restore char at end of section, ret=empty_string, return FALSE
#define RESTORE_E if(e){*e='\n';}
#define SAFE_RETURN RESTORE_E; (*ret)=0; return FALSE
//find valname
int L = strlen(valname);
SearchAgain2:
s = strstr(s,valname); if(!s){SAFE_RETURN;} //find valname
if(s > buf && (*(s-1))!='\n'){s+=L; goto SearchAgain2;} //valname must be at begining of a line!
s+=L; //found valname match, skip past it
while(*s==' ' || *s == '\t'){s++;} //skip spaces and tabs
if(!(*s)){SAFE_RETURN;} //if NULL encounted do safe return
if(*s != '='){goto SearchAgain2;} //no equal sign found after valname, search again
s++; //skip past the equal sign
while(*s==' ' || *s=='\t'){s++;} //skip spaces and tabs
while(*s=='\"' || *s=='\''){s++;} //skip past quotes and ticks
if(!(*s)){SAFE_RETURN;} //if NULL encounted do safe return
char* E = s; //s is now the begining of the valname data
while(*E!='\r' && *E!='\n' && *E!=0){E++;} E--; //find end of line or end of string, then backup 1 char
while(E > s && (*E==' ' || *E=='\t')){E--;} //move backwards past spaces and tabs
while(E > s && (*E=='\"' || *E=='\'')){E--;} //move backwards past quotes and ticks
L = E-s+1; //length of string to extract NOT including NULL
if(L<1 || L+1 > retbuflen){SAFE_RETURN;} //empty string or buffer size too small
strncpy(ret,s,L); //copy the string
ret[L]=0; //null last char on return buffer
RESTORE_E;
return TRUE;
#undef RESTORE_E
#undef SAFE_RETURN
}
How to use... example....
char sFileData[] = "[MySection]\r\n"
"MyValue1 = 123\r\n"
"MyValue2 = 456\r\n"
"MyValue3 = 789\r\n"
"\r\n"
"[MySection]\r\n"
"MyValue1 = Hello1\r\n"
"MyValue2 = Hello2\r\n"
"MyValue3 = Hello3\r\n"
"\r\n";
char str[256];
char* sSec = sFileData;
char secName[] = "[MySection]"; //we support sections with same name
while(sSec)//while we have a valid sNextSec
{
//print values of the sections
char* next=0;//in case we dont have any sucessful grabs
if(GrabIniValue(sSec,secName,"MyValue1",str,sizeof(str),&next)) { printf("MyValue1 = [%s]\n",str); }
if(GrabIniValue(sSec,secName,"MyValue2",str,sizeof(str),0)) { printf("MyValue2 = [%s]\n",str); }
if(GrabIniValue(sSec,secName,"MyValue3",str,sizeof(str),0)) { printf("MyValue3 = [%s]\n",str); }
printf("\n");
sSec = next; //parse next section, next will be null if no more sections to parse
}
Maybe a late answer..But, worth knowing options..If you need a cross-platform solution , definitely you can try GLIB,, its interesting.. (https://developer.gnome.org/glib/stable/glib-Key-value-file-parser.html)
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I have a C file with multiple inline comments that begin with //.
For example,
u32 Status;
// Read foo peripherals status
Status = foo_periph_status(foo_Instance);
// Check if foo is ready to turn right
if ((Status) & (FOO_STATUS_TURN_RIGHT_MASK)) {
// Get FOO current state
foo_Instance->CurrentState = Foo_GetCurrentState(incoming_data);
// Get FOO format
foo_Instance->CurrentState.metadata.Format = Foo_GetFormat(incoming_data)
In above code I'll like to change all the // inline comments from their current format to a /* Inline comments */ format.
I've tried to used,
s/\([^.*]\)\(\/\/\)\(.*\)\($\)/\1\/\*\3 \*\//
and this works for me now.
I'm wondering if there is a better way of doing this?
EDIT :
See this old answer that is much better than mine (also written in C): https://stackoverflow.com/a/12000755/6872717.
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
#define ARRAY_SSIZE(arr) ((ptrdiff_t)ARRAY_SIZE(arr))
// Read line from file
fgets(buff, BUFSIZ, fp_r);
// Find "//" comment
p = strstr(buff, "//");
if (!p)
continue;
// If comment is at the very end of the buffer, and wouldn't fit, remove it.
if ((p - &buff[0] + strlen("/**/\n") + 1) > ARRAY_SSIZE(buff)) {
sprintf(p, "\n");
continue;
}
// Remove "*/" that would break the new comment format
do {
q = strstr(p, "*/");
if (q)
memmove(q, q + strlen("*/"), strlen(q + strlen("*/")) + 1);
} while (q);
// Write the new comment begining
sprintf(p, "/*");
// Find end of line
p = strrchr(buff, '\n');
// Check that the closing "*/" fits in the buffer
while ((p - &buff[0] + strlen("*/\n") + 1) > ARRAY_SSIZE(buff))
p--;
// Write closing "*/"
sprintf(p, "*/\n");
// Write line to file
fputs(buff, fp_w);
This will fix a line. You only need to add the code to iterate over the whole file. You need to have two files open: the one you're reading from (fp_r), and a new one (fp_w). You'll have to delete the old file, and after deleting the first one rename the new one with the same name, so that the result is an overwritten file.
This will remove any appearances of */ after the //.
Problems:
It will not handle cases where a comment is written in the "/**/" format and inside of it contains // because it is unlikely, and complicated to solve (see following examples). If this happens, the result may be an invalid comment.
Examples:
a = 7; /* // this will mess everything */
a = /*7*/b; /* // hello, this too */ c=a; // another comment
That's in single lines, and it's already complicated. Just imagine to handle it in multiline comments...
If a // is found within a string literal, the same as above happens. It has a similar difficulty, and it is also unlikely, so I won't bother solving that; it is up to you if you need it :). The result will be invalid code, too
(Thanks to #EdMorton for spotting this one).
It will truncate a line if a comment is so long that it ends near the end of the buffer. However, the resulting comment will be valid.
Proposal for these problems:
Prompt the user if a /* or */ or " is detected within a line that will be modified before actually writing it into the file, show him both the original and the modification (you would need to keep a copy of the original one), and let him decide if he prefers the old line or the new one. And let the user modify manually those lines after this has done most of the job ;-)
The problem with multiline comments (or multiline string literals, bot those are unicorns) would still exist, but maybe you could find another pattern in those, like for example a * at the very beginning of the line. Anyway, the code wouldn't be invalid; just some unwanted changes inside comments would happen.
Another solution might be to prompt the user at every change.
I need to remove duplicates if
key = anything
but NOT
key=anything
the key can be anything too
e.g.
edit_home=home must be in place
while
edit_home = home or even other string must be removed IF edit_home is a duplicate
for all the lines of the document
thank you
p.s. clearer example:
one=you are
two=we are
three_why=8908908
one = good
two = fine
three_4 = best
three_why = win
from that list i only need to keep:
one=you are
two=we are
three_why=8908908
three_4 = best // because three_4 doesn't have a duplicate
I found a method to do it, but I would need a better search list support by regex or a plugin or a direct regex (which I don't know).
That is: I have two files to compare.
One has the full keys, the other has incomplete.
I merge in a new file all the keys from the first file with those ones of the second, in groups (because the keys are in groups e.g. many keys titled one, many titled two and so on...). Then I regex replace all the keys in the new file by
find (.*)(\s\=\s) replace with \1\=
So they all become key=anything
Then I replace everything after = with empty to isolate the keys.
Then remove the duplicates.
At this point I have trouble to do something like
^.*(^keyone\b|^keytwo\b|^keythree\b).*$
to find all those keys in the document I need. So from that I can select all and replace with the correct keys.
Why? Because in this example the keys are 3 only BUT indeed the keys are many and the find field breaks at a certain point.
How to do it right?
Update: I found Toolbucket plugin which allows to search for many strings, but another issue is that in addition to duplicate, I also have to remove the original.
That is, if I find 2 times the same key "one" I have to remove all the lines containing one.
Ctrl + F
Find tab
Find what: ^.*\S=\S.*$
Find All in Current Document
Copy result from result window to a new window (the list of Line 1: Line 2: Line 3: ...)
Ctrl + F
Replace tab
(the following will remove the leading "Line number:" from every line)
Find what: ^.*?\d:\s
Replace with: Empty
ok, after all that i wrote, one solution could be (therefore, once i have the merged keys)
(?m)^(.*)$(?=\r?\n^(?!\1).*(?s).*?\1)
with this i can mark/highlight all the duplicated keys :-) so then i can manage those only, removing them from the first list and adding what remains to the second file...
If someone has a solution with a direct regex will be really appreciated
Here is a commented UltraEdit script for this task.
// Note: This script does not work for large files as it loads the
// entire file content into very limited scripting memory for fast
// processing even with multiple GB of RAM installed.
if (UltraEdit.document.length > 0) // Is any file opened?
{
// Define environment for this script and select entire file content.
UltraEdit.insertMode();
UltraEdit.columnModeOff();
UltraEdit.activeDocument.selectAll();
// Determine line termination used currently in active file.
var sLineTerm = "\r\n";
if (typeof(UltraEdit.activeDocument.lineTerminator) == "number")
{
// The two lines below require UE v16.00 or UES v10.00 or later.
if (UltraEdit.activeDocument.lineTerminator == 1) sLineTerm = "\n";
else if (UltraEdit.activeDocument.lineTerminator == 2) sLineTerm = "\r";
}
else // This version of UE/UES does not offer line terminator property.
{
if (UltraEdit.activeDocument.selection.indexOf(sLineTerm) < 0)
{
sLineTerm = "\n"; // Not DOS, perhaps UNIX.
if (UltraEdit.activeDocument.selection.indexOf(sLineTerm) < 0)
{
sLineTerm = "\r"; // Also not UNIX, perhaps MAC.
if (UltraEdit.activeDocument.selection.indexOf(sLineTerm) < 0)
{
sLineTerm = "\r\n"; // No line terminator, use DOS.
}
}
}
}
// Get all lines of active file into an array of strings
// with each string being one line from active file.
var asLines = UltraEdit.activeDocument.selection.split(sLineTerm);
var nTotalLines = asLines.length;
// Process each line in the array.
for(var nCurrentLine = 0; nCurrentLine < asLines.length; nCurrentLine++)
{
// Skip all lines not containing or starting with an equal sign.
if (asLines[nCurrentLine].indexOf('=') < 1) continue;
// Get string left to equal sign with tabs/spaces trimmed.
var sKey = asLines[nCurrentLine].replace(/^[\t ]*([^\t =]+).*$/,"$1");
// Skip lines beginning with just tabs/spaces left to equal sign.
if (sKey.length == asLines[nCurrentLine].length) continue;
var_dump(sKey);
// Build the regular expression for the search in all other lines.
var rRegSearch = new RegExp("^[\\t ]*"+sKey+"[\\t ]*=","g");
// Ceck all remaining lines for a line also starting with
// this key string case-sensitive with left to an equal sign.
var nLineCompare = nCurrentLine + 1;
while(nLineCompare < asLines.length)
{
// Does this line also has this key left to equal
// sign with or without surrounding spaces/tabs?
if (asLines[nLineCompare].search(rRegSearch) < 0)
{
nLineCompare++; // No, continue on next line.
}
else // Yes, remove this line from array.
{
asLines.splice(nLineCompare,1);
}
}
}
// Was any line removed from the array?
if (nTotalLines == asLines.length)
{
UltraEdit.activeDocument.top(); // Cancel the selection.
UltraEdit.messageBox("Nothing found to remove!");
}
else
{
// If version of UE/UES supports direct write to clipboard, use
// user clipboard 9 to paste the lines into file with overwritting
// everything as this is much faster than using write command in
// older versions of UE/UES.
if (typeof(UltraEdit.clipboardContent) == "string")
{
var nActiveClipboard = UltraEdit.clipboardIdx;
UltraEdit.selectClipboard(9);
UltraEdit.clipboardContent = asLines.join(sLineTerm);
UltraEdit.activeDocument.paste();
UltraEdit.clearClipboard();
UltraEdit.selectClipboard(nActiveClipboard);
}
else UltraEdit.activeDocument.write(asLines.join(sLineTerm));
var nRemoved = nTotalLines - asLines.length;
UltraEdit.activeDocument.top();
UltraEdit.messageBox("Removed " + nRemoved + " line" + ((nRemoved != 1) ? "s" : "") + " on updated file.");
}
}
Copy this code and paste it into a new ASCII file using DOS line terminators in UltraEdit.
Next use command File - Save As to save the script file for example with name RemoveDuplicateKeys.js into %AppData%\IDMComp\UltraEdit\MyScripts or wherever you want to have saved your UltraEdit scripts.
Open Scripting - Scripts and add the just saved UltraEdit script to the list of scripts. You can enter a description for this script, too.
Open the file with the list, or make this file active if it is already opened in UltraEdit.
Run the script by clicking on it in menu Scripting, or by opening Views - Views/Lists - Script List and double clicking on the script.
This question already has answers here:
c++ compile error: ISO C++ forbids comparison between pointer and integer
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Closed 5 years ago.
How to read a string one char at the time, and stop when you reach end of line? I'am using fgetc function to read from file and put chars to array (latter will change array to malloc), but can't figure out how to stop when the end of line is reached
Tried this (c is the variable with char from file):
if(c=="\0")
But it gives error that I cant compare pointer to integer
File looks like (the length of the words are unknown):
one
two
three
So here comes the questions:
1) Can I compare c with \0 as \0 is two symbols (\ and 0) or is it counted as one (same question with \n)
2) Maybe I should use \n ?
3) If suggestions above are wrong what would you suggest (note I must read string one char at the time)
(Note I am pretty new to C++(and programming it self))
You want to use single quotes:
if(c=='\0')
Double quotes (") are for strings, which are sequences of characters. Single quotes (') are for individual characters.
However, the end-of-line is represented by the newline character, which is '\n'.
Note that in both cases, the backslash is not part of the character, but just a way you represent special characters. Using backslashes you can represent various unprintable characters and also characters which would otherwise confuse the compiler.
The answer to your original question
How to read a string one char at the time, and stop when you reach end of line?
is, in C++, very simply, namely: use getline. The link shows a simple example:
#include <iostream>
#include <string>
int main () {
std::string name;
std::cout << "Please, enter your full name: ";
std::getline (std::cin,name);
std::cout << "Hello, " << name << "!\n";
return 0;
}
Do you really want to do this in C? I wouldn't! The thing is, in C, you have to allocate the memory in which to place the characters you read in? How many characters? You don't know ahead of time. If you allocate too few characters, you will have to allocate a new buffer every time to realize you reading more characters than you made room for. If you over-allocate, you are wasting space.
C is a language for low-level programming. If you are new to programming and writing simple applications for reading files line-by-line, just use C++. It does all that memory allocation for you.
Your later questions regarding "\0" and end-of-lines in general were answered by others and do apply to C as well as C++. But if you are using C, please remember that it's not just the end-of-line that matters, but memory allocation as well. And you will have to be careful not to overrun your buffer.
If you are using C function fgetc then you should check a next character whether it is equal to the new line character or to EOF. For example
unsigned int count = 0;
while ( 1 )
{
int c = fgetc( FileStream );
if ( c == EOF || c == '\n' )
{
printF( "The length of the line is %u\n", count );
count = 0;
if ( c == EOF ) break;
}
else
{
++count;
}
}
or maybe it would be better to rewrite the code using do-while loop. For example
unsigned int count = 0;
do
{
int c = fgetc( FileStream );
if ( c == EOF || c == '\n' )
{
printF( "The length of the line is %u\n", count );
count = 0;
}
else
{
++count;
}
} while ( c != EOF );
Of course you need to insert your own processing of read xgaracters. It is only an example how you could use function fgetc to read lines of a file.
But if the program is written in C++ then it would be much better if you would use std::ifstream and std::string classes and function std::getline to read a whole line.
A text file does not have \0 at the end of lines. It has \n. \n is a character, not a string, so it must be enclosed in single quotes
if (c == '\n')
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I got a little bit of trouble creating a program that edits text in C++. Keep in mind that I'm still at the beginning of programing. Here is what I must do:
Some text is placed in text file F. I must write a program-editor, which based on the file F, commands and data from the keyboard creates the file FF. The program-editor must recognize and process the following commands:
AN - insert text after the n-th row;
IN - insert text before the n-th row;
CM,N - substitution of the rows from m-th to n-th;
DM,N - deleting the rows from m-th to n-th;
E - end of editing;
where m and n are the number of rows in the file F.The commands are recorded one on row and are made as a menu.
This is the program. I researched a lot in the web about text editing and there are some text editing programs' source codes, but I guess I'm still in the beginning of programing and I find those source codes really difficult to understand. I'm concerned about few things:
Must I manually put text in the text file F and must I add another option in the menu about adding text;
The other thing is about the commands - how do I find and use the different rows from the text so I can insert, substitute and delete rows;
Well that is all. If you have the time please help me, because I really need to know how this program must be done in a not so complicated way and I think it got some valuable things that I could learn from it. Thanks in advance !
In pseudo-code, you ll find every real function you ll need in the documpentation.:
You ll need to write parse() yourself, all vec.something and input.something are real vector or string function, under a different name, you ll need to search the documentation.
open, close and writeinfile are io function under different name too (and different parameters), again, see the doc
getuserinput is also a renamed basic io function.
The reason I write this is to give you an idea of how to do this, it is not the solution spoon feeded to you, think of it as the algorithm, if you can do your homework without it, it is far better than using it. Also, learn to search the doc, it is really useful
vector<string> vec
int n, m
string input, output
//Open the file
open(your_file)
//Store every line in a string in the vector
while(input != EOF)
{
input = getalinefrom(file)
vec.add(input)
}
//You don t need the file for now, so close it
close(file)
//Create your 'menu', presuming text based, if graphical, well...
do
{
//Get user choice
input = getuserinput()
//Every command is just a letter, so check it to know what to do
if(input.firstchar == 'A')
{
//Parse the input to get n
n = parse(input)
//Get the line to add
input = getuserinput()
//Add it before n
vec.addafter(n, input)
}
else if (input.firstchar == 'I')
{
//Parse the input to get n
n = parse(input)
//Get the line to add
input = getuserinput()
//Add it before n
vec.addbefore(n, input)
}
else if (input.firstchar == 'C')
{
//Well, I don t see what is substitution so I ll let you try
}
else if (input.firstchar == 'D')
{
//Get n and m
n = parse(input)
m = parse(input)
//Presuming n < m, you ll need to check for error
while(n < m)
{
vec.deleterow(n)
n = n + 1
}
}
//Go out of the loop at E since it s the end of the app
}while(input != "E");
//Concatene every line
n = 0
do
{
output = output + vec.contentofrow(n)
}while(n < vec.length)
//Open the file again, with correct flag it will erase it content
open(file)
//Write your new content
writeinfile(file, output)
//Close the file
close(file)
return 0;
I just need a little help with file parsing. We have to parse a file that has 6 string entries per row in the format:
"string1", "string2", "string3", "string4", "string5", "string6"
My instructor recently gave us a little piece of code as a "hint," and I'm supposed to use it. Unfortunately, I can't figure out how to get it to work. Here's my file parsing function.
void parseData(ifstream &myFile, Book bookPtr[])
{
string bookInfo;
int start, end;
string bookData[6];
getline(myFile, bookInfo);
start = -2;
myFile.open("Book List.txt");
for (int j = 0; j < 6; j++)
{
start += 3;
end = bookInfo.find('"', start);
bookData[j] = bookInfo.substr(start, end-start);
start = end;
}
}
So I'm trying to read the 6 strings into an array of strings. Can someone please help walk me through the process?
start = -2;
for (int j = 0; j < 6; j++)
{
start += 3;
end = bookInfo.find('"', start);
bookData[j] = bookInfo.substr(start, end-start);
start = end;
}
So ", " is four characters. The leading closing quote is 3 characters behind the opening closing quote.
At entry to the loop start is pointing to the last closing quote. (On first entry to loop it is faked as -2 to be pointing to the closing quote of the imaginary "-1th" element.)
So we advance from the last closing quote to the following opening quote:
start += 3;
Then we use std::string::find to find the closing quote:
end = bookInfo.find('"', start);
The offset tells it to ignore all characters up to and including that position.
We then have the two quote positions, start..end, so we use substr to extract the string:
bookData[j] = bookInfo.substr(start, end-start);
And we then update start for the next loop to be the last closing quote:
start = end
Please, for your own sake, create a minimal example. This starts with a string like the line you gave as example and ends with the different parts in an array. Leave the loading from a file out for now, getline() seems to work for you, or? Then, do not declare every variable you might want to use at the beginning of a function. This is not ancient C, where you simply had to do that or introduce additional {} blocks. There is another thing odd, and that is the Book bookPtr[]. This is indeed just a Book* bookPtr, i.e. you are not passing an array to a function but just a pointer. Don't fall for this misleading syntax, it's a lie! Anyway, you don't seem to be using that pointer to the object(s) of the unknown type anyway.
Concerning the splitting of a line into strings, one approach is to locate pairs of double quotes. Everything in between is one of the strings, everything without is irrelevant. The string class has a find() function which optionally takes a starting position. Starting position is always one behind the previously found position.
Your code above seems to assume that there is exactly one double quote, a comma, a space and another double quote that separates two strings. This isn't 100% clear, I would also be prepared for handling multiple spaces or no space at all. Also, is the comma guaranteed? Are the double quotes guaranteed? Anyway, keep it simple. Unless you get a better spec on the input, just assume that only the parts between the quotes is what differs.
Then, what exactly works and what doesn't? You need to ask more specific questions and give more detailed information. The code above doesn't look broken per se, although there are a few things a bit off. For example, you don't typically pass ifstreams to a function, but use the istream baseclass. In your case, you read a line from that file and then open another file using the same fstream object, which doesn't make sense to me, since you don't use it after that. If you only needed that stream locally, you would create and open it there (handling errors of course!) and pass in the filename as parameter only.