strTok function (thread safe, supports empty tokens, doesn't change string)





.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ margin-bottom:0;
}







2












$begingroup$


I'm new to C language and want to explode a string like we do in PHP explode() function, I searched for a built-in function with the C standard library, and I found strtok , but It doesn't support empty tokens like 1,2,3,,5 . Inspired by the answers I found in this SO question I made this function, it is supposed to be thread safe and support empty tokens and doesn't change the original string



char* strTok(char** newString, char* delimiter)

{

    char* string = *newString;

    char* delimiterFound = (char*) 0;

    int tokLenght = 0;

    char* tok = (char*) 0;



    if(!string) return (char*) 0;



    delimiterFound = strstr(string, delimiter);



    if(delimiterFound){

        tokLenght = delimiterFound-string;

    }else{

        tokLenght = strlen(string);

    }



    tok = malloc(tokLenght + 1);

    memcpy(tok, string, tokLenght);

    tok[tokLenght] = '';



    *newString = delimiterFound ? delimiterFound + strlen(delimiter) : (char*)0;



    return tok;

}


I designed it to be used like



char* input = "1,2,3,4,5,6,7,,,10,";

char** inputP = &input;

char* tok;

while( (tok=strTok(inputP, ",")) ){

    printf("%sn", tok);

}





beginner c strings







share|improve this question









$endgroup$








  • 1




    $begingroup$
    Better user-interface then the original strtok. You may be interested in strsep, too. code.woboq.org/userspace/glibc/string/strsep.c.html
    $endgroup$
    – Neil Edelman
    2 hours ago










  • $begingroup$
    @NeilEdelman thanks I never saw this function before, I will check it.
    $endgroup$
    – Accountant م
    2 hours ago






  • 1




    $begingroup$
    It's not in the standard C libraries, but in POSIX, (any type of gcc.) However, like strtok, it obliterates the char to replace it with , so it's not the same.
    $endgroup$
    – Neil Edelman
    2 hours ago


















2












$begingroup$


I'm new to C language and want to explode a string like we do in PHP explode() function, I searched for a built-in function with the C standard library, and I found strtok , but It doesn't support empty tokens like 1,2,3,,5 . Inspired by the answers I found in this SO question I made this function, it is supposed to be thread safe and support empty tokens and doesn't change the original string



char* strTok(char** newString, char* delimiter)

{

    char* string = *newString;

    char* delimiterFound = (char*) 0;

    int tokLenght = 0;

    char* tok = (char*) 0;



    if(!string) return (char*) 0;



    delimiterFound = strstr(string, delimiter);



    if(delimiterFound){

        tokLenght = delimiterFound-string;

    }else{

        tokLenght = strlen(string);

    }



    tok = malloc(tokLenght + 1);

    memcpy(tok, string, tokLenght);

    tok[tokLenght] = '';



    *newString = delimiterFound ? delimiterFound + strlen(delimiter) : (char*)0;



    return tok;

}


I designed it to be used like



char* input = "1,2,3,4,5,6,7,,,10,";

char** inputP = &input;

char* tok;

while( (tok=strTok(inputP, ",")) ){

    printf("%sn", tok);

}





beginner c strings







share|improve this question









$endgroup$








  • 1




    $begingroup$
    Better user-interface then the original strtok. You may be interested in strsep, too. code.woboq.org/userspace/glibc/string/strsep.c.html
    $endgroup$
    – Neil Edelman
    2 hours ago










  • $begingroup$
    @NeilEdelman thanks I never saw this function before, I will check it.
    $endgroup$
    – Accountant م
    2 hours ago






  • 1




    $begingroup$
    It's not in the standard C libraries, but in POSIX, (any type of gcc.) However, like strtok, it obliterates the char to replace it with , so it's not the same.
    $endgroup$
    – Neil Edelman
    2 hours ago














2












2








2





$begingroup$


I'm new to C language and want to explode a string like we do in PHP explode() function, I searched for a built-in function with the C standard library, and I found strtok , but It doesn't support empty tokens like 1,2,3,,5 . Inspired by the answers I found in this SO question I made this function, it is supposed to be thread safe and support empty tokens and doesn't change the original string



char* strTok(char** newString, char* delimiter)

{

    char* string = *newString;

    char* delimiterFound = (char*) 0;

    int tokLenght = 0;

    char* tok = (char*) 0;



    if(!string) return (char*) 0;



    delimiterFound = strstr(string, delimiter);



    if(delimiterFound){

        tokLenght = delimiterFound-string;

    }else{

        tokLenght = strlen(string);

    }



    tok = malloc(tokLenght + 1);

    memcpy(tok, string, tokLenght);

    tok[tokLenght] = '';



    *newString = delimiterFound ? delimiterFound + strlen(delimiter) : (char*)0;



    return tok;

}


I designed it to be used like



char* input = "1,2,3,4,5,6,7,,,10,";

char** inputP = &input;

char* tok;

while( (tok=strTok(inputP, ",")) ){

    printf("%sn", tok);

}





beginner c strings







share|improve this question









$endgroup$




I'm new to C language and want to explode a string like we do in PHP explode() function, I searched for a built-in function with the C standard library, and I found strtok , but It doesn't support empty tokens like 1,2,3,,5 . Inspired by the answers I found in this SO question I made this function, it is supposed to be thread safe and support empty tokens and doesn't change the original string



char* strTok(char** newString, char* delimiter)

{

    char* string = *newString;

    char* delimiterFound = (char*) 0;

    int tokLenght = 0;

    char* tok = (char*) 0;



    if(!string) return (char*) 0;



    delimiterFound = strstr(string, delimiter);



    if(delimiterFound){

        tokLenght = delimiterFound-string;

    }else{

        tokLenght = strlen(string);

    }



    tok = malloc(tokLenght + 1);

    memcpy(tok, string, tokLenght);

    tok[tokLenght] = '';



    *newString = delimiterFound ? delimiterFound + strlen(delimiter) : (char*)0;



    return tok;

}


I designed it to be used like



char* input = "1,2,3,4,5,6,7,,,10,";

char** inputP = &input;

char* tok;

while( (tok=strTok(inputP, ",")) ){

    printf("%sn", tok);

}





beginner c strings




beginner c strings






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked 4 hours ago









Accountant مAccountant م

1727




1727








  • 1




    $begingroup$
    Better user-interface then the original strtok. You may be interested in strsep, too. code.woboq.org/userspace/glibc/string/strsep.c.html
    $endgroup$
    – Neil Edelman
    2 hours ago










  • $begingroup$
    @NeilEdelman thanks I never saw this function before, I will check it.
    $endgroup$
    – Accountant م
    2 hours ago






  • 1




    $begingroup$
    It's not in the standard C libraries, but in POSIX, (any type of gcc.) However, like strtok, it obliterates the char to replace it with , so it's not the same.
    $endgroup$
    – Neil Edelman
    2 hours ago














  • 1




    $begingroup$
    Better user-interface then the original strtok. You may be interested in strsep, too. code.woboq.org/userspace/glibc/string/strsep.c.html
    $endgroup$
    – Neil Edelman
    2 hours ago










  • $begingroup$
    @NeilEdelman thanks I never saw this function before, I will check it.
    $endgroup$
    – Accountant م
    2 hours ago






  • 1




    $begingroup$
    It's not in the standard C libraries, but in POSIX, (any type of gcc.) However, like strtok, it obliterates the char to replace it with , so it's not the same.
    $endgroup$
    – Neil Edelman
    2 hours ago








1




1




$begingroup$
Better user-interface then the original strtok. You may be interested in strsep, too. code.woboq.org/userspace/glibc/string/strsep.c.html
$endgroup$
– Neil Edelman
2 hours ago




$begingroup$
Better user-interface then the original strtok. You may be interested in strsep, too. code.woboq.org/userspace/glibc/string/strsep.c.html
$endgroup$
– Neil Edelman
2 hours ago












$begingroup$
@NeilEdelman thanks I never saw this function before, I will check it.
$endgroup$
– Accountant م
2 hours ago




$begingroup$
@NeilEdelman thanks I never saw this function before, I will check it.
$endgroup$
– Accountant م
2 hours ago




1




1




$begingroup$
It's not in the standard C libraries, but in POSIX, (any type of gcc.) However, like strtok, it obliterates the char to replace it with , so it's not the same.
$endgroup$
– Neil Edelman
2 hours ago




$begingroup$
It's not in the standard C libraries, but in POSIX, (any type of gcc.) However, like strtok, it obliterates the char to replace it with , so it's not the same.
$endgroup$
– Neil Edelman
2 hours ago










2 Answers
2






active

oldest

votes


















1












$begingroup$


  • delimiterFound + strlen(delimiter) sounds like a bug. If the delimiter is longer than one character, *newString will point too far into the original, maybe even beyond the end. Correct me if I am wrong, delimiterFound + 1 is what you are actually after.



  • Modern C allows, and strongly encourages, to declare variables as close to their use a possible. Consider



    char * delimiterFound = strstr(string, delimiter);
    
....
    
char * tok = malloc(tokLenght + 1);


    etc.



  • Always test that malloc didn't fail.



  • More spaces - around keywords, braces, etc - definitely improve readability:



        if (....) {
    
        ....
    
    } else {
    
        ....
    
    }







share|improve this answer









$endgroup$









  • 1




    $begingroup$
    Thaaank you very much for these precious points, regarding the delimiter length bug, ummmm, I want to support long delimiters more than 1 characters like the boundary string in http requests that has content-type multi-part, and I don't think it's a bug because delimiterFound + strlen(delimiter) can never be after the 0 byte that terminates the original string!, right ? "fooDELIMITER" 3 + 12
    $endgroup$
    – Accountant م
    2 hours ago










  • $begingroup$
    @Accountantم Long delimiters here refer to, say ",;.", in where any character delimits the string on its own right.
    $endgroup$
    – vnp
    2 hours ago










  • $begingroup$
    I didn't get it, I'm sorry, can you please give me an example input that can break this code, exploiting this bug ?
    $endgroup$
    – Accountant م
    2 hours ago






  • 1




    $begingroup$
    @Accountantم Sorry for not being clear. I should realize that your intentions are different (and read man strstr more carefully). Consider it my blinder - since you mentioned strtok, I expected the strtok semantics.
    $endgroup$
    – vnp
    2 hours ago










  • $begingroup$
    It's my fault because I said it's strtok, I wanted strtok that can support delimiters more than 1 characters, because I need this feature a lot. So do you mean it's not a bug ??
    $endgroup$
    – Accountant م
    2 hours ago



















1












$begingroup$

From a readability viewpoint, you should use NULL instead of (char*) 0 as it is easier to recognize what you're trying to do. Also, the tokLenght misspells "length", and should probably be tokLength.



You leak memory, as the memory allocated to hold the returned string is never freed.






share|improve this answer









$endgroup$













  • $begingroup$
    Thank you very much I will use NULL from now on, and I will remember to free() memory , 'I miss PHP garbage collector :(', I didn't get the tokLength spelling note, aren't they the same ?
    $endgroup$
    – Accountant م
    2 hours ago








  • 1




    $begingroup$
    It's a matter of style, and including .h if you want to use NULL. However, you don't have to cast (char *)0, just use 0 (or NULL.) It knows from the return type.
    $endgroup$
    – Neil Edelman
    2 hours ago












Your Answer





StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
});
});
}, "mathjax-editing");

StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "196"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f216956%2fstrtok-function-thread-safe-supports-empty-tokens-doesnt-change-string%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























2 Answers
2






active

oldest

votes








2 Answers
2






active

oldest

votes









active

oldest

votes






active

oldest

votes









1












$begingroup$


  • delimiterFound + strlen(delimiter) sounds like a bug. If the delimiter is longer than one character, *newString will point too far into the original, maybe even beyond the end. Correct me if I am wrong, delimiterFound + 1 is what you are actually after.



  • Modern C allows, and strongly encourages, to declare variables as close to their use a possible. Consider



    char * delimiterFound = strstr(string, delimiter);
    
....
    
char * tok = malloc(tokLenght + 1);


    etc.



  • Always test that malloc didn't fail.



  • More spaces - around keywords, braces, etc - definitely improve readability:



        if (....) {
    
        ....
    
    } else {
    
        ....
    
    }







share|improve this answer









$endgroup$









  • 1




    $begingroup$
    Thaaank you very much for these precious points, regarding the delimiter length bug, ummmm, I want to support long delimiters more than 1 characters like the boundary string in http requests that has content-type multi-part, and I don't think it's a bug because delimiterFound + strlen(delimiter) can never be after the 0 byte that terminates the original string!, right ? "fooDELIMITER" 3 + 12
    $endgroup$
    – Accountant م
    2 hours ago










  • $begingroup$
    @Accountantم Long delimiters here refer to, say ",;.", in where any character delimits the string on its own right.
    $endgroup$
    – vnp
    2 hours ago










  • $begingroup$
    I didn't get it, I'm sorry, can you please give me an example input that can break this code, exploiting this bug ?
    $endgroup$
    – Accountant م
    2 hours ago






  • 1




    $begingroup$
    @Accountantم Sorry for not being clear. I should realize that your intentions are different (and read man strstr more carefully). Consider it my blinder - since you mentioned strtok, I expected the strtok semantics.
    $endgroup$
    – vnp
    2 hours ago










  • $begingroup$
    It's my fault because I said it's strtok, I wanted strtok that can support delimiters more than 1 characters, because I need this feature a lot. So do you mean it's not a bug ??
    $endgroup$
    – Accountant م
    2 hours ago
















1












$begingroup$


  • delimiterFound + strlen(delimiter) sounds like a bug. If the delimiter is longer than one character, *newString will point too far into the original, maybe even beyond the end. Correct me if I am wrong, delimiterFound + 1 is what you are actually after.



  • Modern C allows, and strongly encourages, to declare variables as close to their use a possible. Consider



    char * delimiterFound = strstr(string, delimiter);
    
....
    
char * tok = malloc(tokLenght + 1);


    etc.



  • Always test that malloc didn't fail.



  • More spaces - around keywords, braces, etc - definitely improve readability:



        if (....) {
    
        ....
    
    } else {
    
        ....
    
    }







share|improve this answer









$endgroup$









  • 1




    $begingroup$
    Thaaank you very much for these precious points, regarding the delimiter length bug, ummmm, I want to support long delimiters more than 1 characters like the boundary string in http requests that has content-type multi-part, and I don't think it's a bug because delimiterFound + strlen(delimiter) can never be after the 0 byte that terminates the original string!, right ? "fooDELIMITER" 3 + 12
    $endgroup$
    – Accountant م
    2 hours ago










  • $begingroup$
    @Accountantم Long delimiters here refer to, say ",;.", in where any character delimits the string on its own right.
    $endgroup$
    – vnp
    2 hours ago










  • $begingroup$
    I didn't get it, I'm sorry, can you please give me an example input that can break this code, exploiting this bug ?
    $endgroup$
    – Accountant م
    2 hours ago






  • 1




    $begingroup$
    @Accountantم Sorry for not being clear. I should realize that your intentions are different (and read man strstr more carefully). Consider it my blinder - since you mentioned strtok, I expected the strtok semantics.
    $endgroup$
    – vnp
    2 hours ago










  • $begingroup$
    It's my fault because I said it's strtok, I wanted strtok that can support delimiters more than 1 characters, because I need this feature a lot. So do you mean it's not a bug ??
    $endgroup$
    – Accountant م
    2 hours ago














1












1








1





$begingroup$


  • delimiterFound + strlen(delimiter) sounds like a bug. If the delimiter is longer than one character, *newString will point too far into the original, maybe even beyond the end. Correct me if I am wrong, delimiterFound + 1 is what you are actually after.



  • Modern C allows, and strongly encourages, to declare variables as close to their use a possible. Consider



    char * delimiterFound = strstr(string, delimiter);
    
....
    
char * tok = malloc(tokLenght + 1);


    etc.



  • Always test that malloc didn't fail.



  • More spaces - around keywords, braces, etc - definitely improve readability:



        if (....) {
    
        ....
    
    } else {
    
        ....
    
    }







share|improve this answer









$endgroup$




  • delimiterFound + strlen(delimiter) sounds like a bug. If the delimiter is longer than one character, *newString will point too far into the original, maybe even beyond the end. Correct me if I am wrong, delimiterFound + 1 is what you are actually after.



  • Modern C allows, and strongly encourages, to declare variables as close to their use a possible. Consider



    char * delimiterFound = strstr(string, delimiter);
    
....
    
char * tok = malloc(tokLenght + 1);


    etc.



  • Always test that malloc didn't fail.



  • More spaces - around keywords, braces, etc - definitely improve readability:



        if (....) {
    
        ....
    
    } else {
    
        ....
    
    }








share|improve this answer












share|improve this answer



share|improve this answer










answered 3 hours ago









vnpvnp

40.6k233103




40.6k233103








  • 1




    $begingroup$
    Thaaank you very much for these precious points, regarding the delimiter length bug, ummmm, I want to support long delimiters more than 1 characters like the boundary string in http requests that has content-type multi-part, and I don't think it's a bug because delimiterFound + strlen(delimiter) can never be after the 0 byte that terminates the original string!, right ? "fooDELIMITER" 3 + 12
    $endgroup$
    – Accountant م
    2 hours ago










  • $begingroup$
    @Accountantم Long delimiters here refer to, say ",;.", in where any character delimits the string on its own right.
    $endgroup$
    – vnp
    2 hours ago










  • $begingroup$
    I didn't get it, I'm sorry, can you please give me an example input that can break this code, exploiting this bug ?
    $endgroup$
    – Accountant م
    2 hours ago






  • 1




    $begingroup$
    @Accountantم Sorry for not being clear. I should realize that your intentions are different (and read man strstr more carefully). Consider it my blinder - since you mentioned strtok, I expected the strtok semantics.
    $endgroup$
    – vnp
    2 hours ago










  • $begingroup$
    It's my fault because I said it's strtok, I wanted strtok that can support delimiters more than 1 characters, because I need this feature a lot. So do you mean it's not a bug ??
    $endgroup$
    – Accountant م
    2 hours ago














  • 1




    $begingroup$
    Thaaank you very much for these precious points, regarding the delimiter length bug, ummmm, I want to support long delimiters more than 1 characters like the boundary string in http requests that has content-type multi-part, and I don't think it's a bug because delimiterFound + strlen(delimiter) can never be after the 0 byte that terminates the original string!, right ? "fooDELIMITER" 3 + 12
    $endgroup$
    – Accountant م
    2 hours ago










  • $begingroup$
    @Accountantم Long delimiters here refer to, say ",;.", in where any character delimits the string on its own right.
    $endgroup$
    – vnp
    2 hours ago










  • $begingroup$
    I didn't get it, I'm sorry, can you please give me an example input that can break this code, exploiting this bug ?
    $endgroup$
    – Accountant م
    2 hours ago






  • 1




    $begingroup$
    @Accountantم Sorry for not being clear. I should realize that your intentions are different (and read man strstr more carefully). Consider it my blinder - since you mentioned strtok, I expected the strtok semantics.
    $endgroup$
    – vnp
    2 hours ago










  • $begingroup$
    It's my fault because I said it's strtok, I wanted strtok that can support delimiters more than 1 characters, because I need this feature a lot. So do you mean it's not a bug ??
    $endgroup$
    – Accountant م
    2 hours ago








1




1




$begingroup$
Thaaank you very much for these precious points, regarding the delimiter length bug, ummmm, I want to support long delimiters more than 1 characters like the boundary string in http requests that has content-type multi-part, and I don't think it's a bug because delimiterFound + strlen(delimiter) can never be after the 0 byte that terminates the original string!, right ? "fooDELIMITER" 3 + 12
$endgroup$
– Accountant م
2 hours ago




$begingroup$
Thaaank you very much for these precious points, regarding the delimiter length bug, ummmm, I want to support long delimiters more than 1 characters like the boundary string in http requests that has content-type multi-part, and I don't think it's a bug because delimiterFound + strlen(delimiter) can never be after the 0 byte that terminates the original string!, right ? "fooDELIMITER" 3 + 12
$endgroup$
– Accountant م
2 hours ago












$begingroup$
@Accountantم Long delimiters here refer to, say ",;.", in where any character delimits the string on its own right.
$endgroup$
– vnp
2 hours ago




$begingroup$
@Accountantم Long delimiters here refer to, say ",;.", in where any character delimits the string on its own right.
$endgroup$
– vnp
2 hours ago












$begingroup$
I didn't get it, I'm sorry, can you please give me an example input that can break this code, exploiting this bug ?
$endgroup$
– Accountant م
2 hours ago




$begingroup$
I didn't get it, I'm sorry, can you please give me an example input that can break this code, exploiting this bug ?
$endgroup$
– Accountant م
2 hours ago




1




1




$begingroup$
@Accountantم Sorry for not being clear. I should realize that your intentions are different (and read man strstr more carefully). Consider it my blinder - since you mentioned strtok, I expected the strtok semantics.
$endgroup$
– vnp
2 hours ago




$begingroup$
@Accountantم Sorry for not being clear. I should realize that your intentions are different (and read man strstr more carefully). Consider it my blinder - since you mentioned strtok, I expected the strtok semantics.
$endgroup$
– vnp
2 hours ago












$begingroup$
It's my fault because I said it's strtok, I wanted strtok that can support delimiters more than 1 characters, because I need this feature a lot. So do you mean it's not a bug ??
$endgroup$
– Accountant م
2 hours ago




$begingroup$
It's my fault because I said it's strtok, I wanted strtok that can support delimiters more than 1 characters, because I need this feature a lot. So do you mean it's not a bug ??
$endgroup$
– Accountant م
2 hours ago













1












$begingroup$

From a readability viewpoint, you should use NULL instead of (char*) 0 as it is easier to recognize what you're trying to do. Also, the tokLenght misspells "length", and should probably be tokLength.



You leak memory, as the memory allocated to hold the returned string is never freed.






share|improve this answer









$endgroup$













  • $begingroup$
    Thank you very much I will use NULL from now on, and I will remember to free() memory , 'I miss PHP garbage collector :(', I didn't get the tokLength spelling note, aren't they the same ?
    $endgroup$
    – Accountant م
    2 hours ago








  • 1




    $begingroup$
    It's a matter of style, and including .h if you want to use NULL. However, you don't have to cast (char *)0, just use 0 (or NULL.) It knows from the return type.
    $endgroup$
    – Neil Edelman
    2 hours ago
















1












$begingroup$

From a readability viewpoint, you should use NULL instead of (char*) 0 as it is easier to recognize what you're trying to do. Also, the tokLenght misspells "length", and should probably be tokLength.



You leak memory, as the memory allocated to hold the returned string is never freed.






share|improve this answer









$endgroup$













  • $begingroup$
    Thank you very much I will use NULL from now on, and I will remember to free() memory , 'I miss PHP garbage collector :(', I didn't get the tokLength spelling note, aren't they the same ?
    $endgroup$
    – Accountant م
    2 hours ago








  • 1




    $begingroup$
    It's a matter of style, and including .h if you want to use NULL. However, you don't have to cast (char *)0, just use 0 (or NULL.) It knows from the return type.
    $endgroup$
    – Neil Edelman
    2 hours ago














1












1








1





$begingroup$

From a readability viewpoint, you should use NULL instead of (char*) 0 as it is easier to recognize what you're trying to do. Also, the tokLenght misspells "length", and should probably be tokLength.



You leak memory, as the memory allocated to hold the returned string is never freed.






share|improve this answer









$endgroup$



From a readability viewpoint, you should use NULL instead of (char*) 0 as it is easier to recognize what you're trying to do. Also, the tokLenght misspells "length", and should probably be tokLength.



You leak memory, as the memory allocated to hold the returned string is never freed.







share|improve this answer












share|improve this answer



share|improve this answer










answered 3 hours ago









1201ProgramAlarm1201ProgramAlarm

3,6532925




3,6532925












  • $begingroup$
    Thank you very much I will use NULL from now on, and I will remember to free() memory , 'I miss PHP garbage collector :(', I didn't get the tokLength spelling note, aren't they the same ?
    $endgroup$
    – Accountant م
    2 hours ago








  • 1




    $begingroup$
    It's a matter of style, and including .h if you want to use NULL. However, you don't have to cast (char *)0, just use 0 (or NULL.) It knows from the return type.
    $endgroup$
    – Neil Edelman
    2 hours ago


















  • $begingroup$
    Thank you very much I will use NULL from now on, and I will remember to free() memory , 'I miss PHP garbage collector :(', I didn't get the tokLength spelling note, aren't they the same ?
    $endgroup$
    – Accountant م
    2 hours ago








  • 1




    $begingroup$
    It's a matter of style, and including .h if you want to use NULL. However, you don't have to cast (char *)0, just use 0 (or NULL.) It knows from the return type.
    $endgroup$
    – Neil Edelman
    2 hours ago
















$begingroup$
Thank you very much I will use NULL from now on, and I will remember to free() memory , 'I miss PHP garbage collector :(', I didn't get the tokLength spelling note, aren't they the same ?
$endgroup$
– Accountant م
2 hours ago






$begingroup$
Thank you very much I will use NULL from now on, and I will remember to free() memory , 'I miss PHP garbage collector :(', I didn't get the tokLength spelling note, aren't they the same ?
$endgroup$
– Accountant م
2 hours ago






1




1




$begingroup$
It's a matter of style, and including .h if you want to use NULL. However, you don't have to cast (char *)0, just use 0 (or NULL.) It knows from the return type.
$endgroup$
– Neil Edelman
2 hours ago




$begingroup$
It's a matter of style, and including .h if you want to use NULL. However, you don't have to cast (char *)0, just use 0 (or NULL.) It knows from the return type.
$endgroup$
– Neil Edelman
2 hours ago


















draft saved

draft discarded




















































Thanks for contributing an answer to Code Review Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid …



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


Use MathJax to format equations. MathJax reference.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f216956%2fstrtok-function-thread-safe-supports-empty-tokens-doesnt-change-string%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







-

Popular posts from this blog

Усть-Каменогорск

Image
У этого термина существуют и другие значения, см. Усть-Каменогорск. Город Усть-Каменогорск каз. Өскемен Флаг Герб 49°57′ с. ш. 82°37′ в. д. H G Я O L Страна Казахстан   Казахстан Статус областной центр Область Восточно-Казахстанская Аким Жаксылык Омар [1] История и география Основан 1720 Город с 1868 Площадь 303,15 [2] км² Высота центра 283 ± 1 м Тип климата резко-континентальный Часовой пояс UTC+6 Население Население 329 090 [3]  человек ( 2018 ) Национальности русские 53,56 % казахи 42,99 % немцы 0,82 % украинцы 0,57 % татары 0,79 % белорусы 0,14 % азербайджанцы 0,23 % корейцы 0,20 % прочие 1,08 % -1 шт [4] Этнохороним усть-каменогорцы, усть-каменогорец Цифровые идентификаторы Телефонный код +7 (7232) Почтовый индекс F0***** [5] Автомобильный код 16 (ранее F) oskemen.kz Усть-Каменогорск Усть-Каменогорск ...
Read more

Халкинская богословская школа

Image
Халкинская богословская школа тур. Rum Ortodoks Ruhban Okulu греч. Ιερά Θεολογική Σχολή της Χάλκης Главное здание Халкинской школы Международное название Theological School of Halki Год основания 1844 Конфессия православие Церковь Константинопольская Ректор Елпидифор (Ламбриниадис) Расположение о. Хейбелиада, Турция Юридический адрес Ümit tepesi No 5, 34973 Heybeliada, Istanbul, Turkey Сайт www.greece.org  [[commons:Category:Halki seminary|Халкинская богословская школа тур. Rum Ortodoks Ruhban Okulu греч. Ιερά Θεολογική Σχολή της Χάλκης на Викискладе]] Ха́лкинская богосло́вская шко́ла (или Духовная семинария на Халки , тур. Rum Ortodoks Ruhban Okulu , греч. Ιερά Θεολογική Σχολή της Χάλκης ) — недействующее среднее специальное учебное заведение Константинопольской православной церкви, расположенное на территории Свято-Троицкого мужского монастыря на вершине холма Надежды (тур. Ümit Tepesi ) острова Хейбелиада, в Турции....
Read more

Высокополье (Харьковская область)

Image
У этого термина существуют и другие значения, см. Высокополье. Село Высокополье укр. Високопілля Герб 49°55′07″ с. ш. 35°25′13″ в. д. H G Я O L Страна Украина   Украина Область Харьковская Район Валковский Сельский совет Высокопольский История и география Основан 1670 Прежние названия Хмелевое Площадь 55,56 км² Часовой пояс UTC+2, летом UTC+3 Население Население 1957 человек ( 2001 ) Плотность 35,220 чел./км² Цифровые идентификаторы Телефонный код +380 5753 Почтовый индекс 63020 Автомобильный код AX, КХ / 21 КОАТУУ 6321281501 Высокополье Высокополье Высокополье  Аудио, фото и видео на Викискладе Высокопо́лье (укр. Високопілля ) — село, Высокопольский сельский совет, Валковский район, Харьковская область, Украина. Код КОАТУУ — 6321281501. Население по переписи 2001 г. составляет 1957 (866/1091 м/ж) человек. Является административным центр...
Read more