C语言中带分隔符的拆分字符串
在C编程语言中，如何编写函数来拆分并返回带分隔符的字符串的数组C语言中带分隔符的拆分字符串,c,string,split,C,String,Split,在C编程语言中，如何编写函数来拆分并返回带分隔符的字符串的数组 char* str = "JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC"; str_split(str,','); 可以使用该函数拆分字符串（并指定要使用的分隔符）。请注意，strtok（）将修改传递给它的字符串。如果其他地方需要原始字符串，请复制它并将副本传递给strtok（） 编辑： 示例（请注意，它不处理连续分隔符，例如“JAN、、FEB、MAR”）： 字符串标记器此代码应该
char* str = "JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC";
str_split(str,',');
strtok（）strtok（）字符串标记器此代码应该为您提供正确的方向
int main(void) {
char st[] ="Where there is will, there is a way.";
char *ch;
ch = strtok(st, " ");
while (ch != NULL) {
printf("%s\n", ch);
ch = strtok(NULL, " ,");
}
getch();
return 0;
}
在上面的示例中，有一种方法可以返回字符串中以null结尾的字符串数组（如您所希望的）。但是，它不可能传递文本字符串，因为它必须由函数修改：
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
char** str_split( char* str, char delim, int* numSplits )
{
char** ret;
int retLen;
char* c;
if ( ( str == NULL ) ||
( delim == '\0' ) )
{
/* Either of those will cause problems */
ret = NULL;
retLen = -1;
}
else
{
retLen = 0;
c = str;
/* Pre-calculate number of elements */
do
{
if ( *c == delim )
{
retLen++;
}
c++;
} while ( *c != '\0' );
ret = malloc( ( retLen + 1 ) * sizeof( *ret ) );
ret[retLen] = NULL;
c = str;
retLen = 1;
ret[0] = str;
do
{
if ( *c == delim )
{
ret[retLen++] = &c[1];
*c = '\0';
}
c++;
} while ( *c != '\0' );
}
if ( numSplits != NULL )
{
*numSplits = retLen;
}
return ret;
}
int main( int argc, char* argv[] )
{
const char* str = "JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC";
char* strCpy;
char** split;
int num;
int i;
strCpy = malloc( strlen( str ) * sizeof( *strCpy ) );
strcpy( strCpy, str );
split = str_split( strCpy, ',', &num );
if ( split == NULL )
{
puts( "str_split returned NULL" );
}
else
{
printf( "%i Results: \n", num );
for ( i = 0; i < num; i++ )
{
puts( split[i] );
}
}
free( split );
free( strCpy );
return 0;
}
#包括
#包括
#包括
字符**str_分割（字符*str，字符delim，int*numSplits）
{
字符**ret；
内特雷特伦；
char*c；
如果（（str==NULL）||
（delim=='\0'））
{
/*这两种情况都会造成问题*/
ret=NULL；
retLen=-1；
}
其他的
{
retLen=0；
c=str；
/*预先计算元素的数量*/
做
{
如果（*c==delim）
{
retLen++；
}
C++；
}而（*c！='\0'）；
ret=malloc（（retLen+1）*sizeof（*ret））；
ret[retLen]=NULL；
c=str；
retLen=1；
ret[0]=str；
做
{
如果（*c==delim）
{
ret[retLen++]=&c[1]；
*c='\0'；
}
C++；
}而（*c！='\0'）；
}
if（numSplits！=NULL）
{
*numSplits=retLen；
}
返回ret；
}
int main（int argc，char*argv[]）
{
const char*str=“一月、二月、三月、四月、五月、六月、七月、八月、九月、十月、十一月、十二月”；
字符*strCpy；
字符**拆分；
int-num；
int i；
strCpy=malloc（strlen（str）*sizeof（*strCpy））；
strcpy（strcpy，str）；
split=str_split（strCpy，，，&num）；
if（split==NULL）
{
看跌期权（“str_split返回空”）；
}
其他的
{
printf（“%i结果：\n”，num）；
对于（i=0；i也许有一种更简洁的方法可以做到这一点，但你已经明白了。此函数获取一个char*字符串，并通过除数器将其拆分。一排可以有多个除沫器。请注意，该函数修改原始字符串。如果需要原始字符串保持不变，则必须首先复制原始字符串。此函数不使用任何cstring函数调用，因此它可能比其他函数快一点。如果不关心内存分配，可以在函数顶部分配子字符串，使用大小SrLLN（SRCYSTR）/ 2，并且（如C++所提到的）版本跳过函数的下半部分。如果这样做，函数将减少到O（N），但下面显示的内存优化方式是O（2N） 功能：
char** str_split(char *src_str, const char deliminator, size_t &num_sub_str){
//replace deliminator's with zeros and count how many
//sub strings with length >= 1 exist
num_sub_str = 0;
char *src_str_tmp = src_str;
bool found_delim = true;
while(*src_str_tmp){
if(*src_str_tmp == deliminator){
*src_str_tmp = 0;
found_delim = true;
}
else if(found_delim){ //found first character of a new string
num_sub_str++;
found_delim = false;
//sub_str_vec.push_back(src_str_tmp); //for c++
}
src_str_tmp++;
}
printf("Start - found %d sub strings\n", num_sub_str);
if(num_sub_str <= 0){
printf("str_split() - no substrings were found\n");
return(0);
}
//if you want to use a c++ vector and push onto it, the rest of this function
//can be omitted (obviously modifying input parameters to take a vector, etc)
char **sub_strings = (char **)malloc( (sizeof(char*) * num_sub_str) + 1);
const char *src_str_terminator = src_str_tmp;
src_str_tmp = src_str;
bool found_null = true;
size_t idx = 0;
while(src_str_tmp < src_str_terminator){
if(!*src_str_tmp) //found a NULL
found_null = true;
else if(found_null){
sub_strings[idx++] = src_str_tmp;
//printf("sub_string_%d: [%s]\n", idx-1, sub_strings[idx-1]);
found_null = false;
}
src_str_tmp++;
}
sub_strings[num_sub_str] = NULL;
return(sub_strings);
}
char months[] = "JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC";
char *str = strdup(months);
size_t num_sub_str;
char **sub_strings = str_split(str, ',', num_sub_str);
char *endptr;
if(sub_strings){
for(int i = 0; sub_strings[i]; i++)
printf("[%s]\n", sub_strings[i]);
}
free(sub_strings);
free(str);
char **tokens;
int count, i;
const char *str = "JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC";
count = split (str, ',', &tokens);
for (i = 0; i < count; i++) printf ("%s\n", tokens[i]);
/* freeing tokens */
for (i = 0; i < count; i++) free (tokens[i]);
free (tokens);
const char *src = ";b,test,Tèst,;;cd;ελληνικά,nørmälize,;string ｔｏ";
const char *delim = ";,";
bool keepnulls = true;
size_t ntoks = 0;
// destructive (use copy of src)
char *scopy = strdup( src );
if (!scopy) { ... }; // handle strdup failure
printf( "%s\n", src );
char **arrtoks = str_toksarray_alloc( &scopy, delim, &ntoks, keepnulls );
printf( "%lu tokens read\n", ntoks );
if ( arrtoks ) {
for (int i=0; arrtoks[i]; i++) {
printf( "%d: %s\n", i, arrtoks[i] );
}
}
free( scopy );
free( arrtoks );
/* OUTPUT
;b,test,Tèst,;;cd;ελληνικά,nørmälize,;string ｔｏ
11 tokens read
0:
1: b
2: test
3: Tèst
4:
5:
6: cd
7: ελληνικά
8: nørmälize
9:
10: string ｔｏ
*/
// non-destructive
keepnulls = false; // reject empty tokens
printf( "%s\n", src );
arrtoks = str_toksarray_alloc2( src, delim, &ntoks, keepnulls );
printf( "%lu tokens read\n", ntoks );
if ( arrtoks ) {
for (int i=0; arrtoks[i]; i++) {
printf( "%d: %s\n", i, arrtoks[i] );
}
}
toksarray_free2( arrtoks ); // dangling arrtoks
// or: arrtoks = toksarray_free2( arrtoks ); // non-dangling artoks
/* OUTPUT
;b,test,Tèst,;;cd;ελληνικά,nørmälize,;string ｔｏ
7 tokens read
0: b
1: test
2: Tèst
3: cd
4: ελληνικά
5: nørmälize
6: string ｔｏ
*/
// ----------------------------------------
// Tokenize destructively a nul-terminated source-string.
// Return a dynamically allocated, NULL terminated array of char-pointers
// each pointing to each token found in the source-string, or NULL on error.
//
char **str_toksarray_alloc(char **strp, const char *delim, size_t *ntoks, bool keepnulls)
{
// sanity checks
if ( !strp || !*strp || !**strp || !delim ) {
goto failed;
}
char *strpSaved = *strp; // save initial *strp pointer
bool ntoksOk = (ntoks && *ntoks); // false when ntoks is muted
size_t _ntoks = (ntoksOk ? *ntoks : 16); // # of tokens to alloc-ahead
// alloc array of char-pointers (+1 for NULL sentinel)
char **toksarr = malloc( (_ntoks+1) * sizeof(*toksarr) );
if ( !toksarr ) {
goto failed;
}
// Parse *strp tokens into the array
size_t i = 0; // # of actually parsed tokens
char *tok;
while ( (tok = strsep(strp, delim)) ) {
// if requested, ignore empty tokens
if ( *tok == '\0' && !keepnulls ) {
continue;
}
// non-muted ntoks reached? we are done
if ( ntoksOk && i == _ntoks ) {
*ntoks = i;
break;
}
// muted ntoks & ran out of space? double toksarr and keep parsing
if ( !ntoksOk && i == _ntoks ) {
_ntoks *= 2;
char **tmparr = realloc( toksarr, (_ntoks+1) * sizeof(*tmparr) );
if ( !tmparr ) {
*strp = strpSaved;
free( toksarr );
goto failed;
}
toksarr = tmparr;
}
toksarr[i++] = tok; // get token address
}
toksarr[i] = NULL; // NULL sentinel
*strp = strpSaved; // restore initial *strp pointer
if (ntoks) *ntoks = i; // pass to caller # of parsed tokens
return toksarr;
failed:
if (ntoks) *ntoks = 0;
return NULL;
}
// ----------------------------------------
// Tokenize non-destructively a nul-terminated source-string.
// Return a dynamically allocated, NULL terminated array of dynamically
// allocated and nul-terminated string copies of each token found in the
// source-string. Return NULL on error.
// The 2 at the end of the name means 2-levels of allocation.
//
char **str_toksarray_alloc2( const char *str, const char *delim, size_t *ntoks, bool keepnulls )
{
// sanity checks
if ( !str || !*str || !delim ) {
if (ntoks) *ntoks = 0;
return NULL;
}
// make a copy of str to work with
char *_str = strdup( str );
if ( !_str ) {
if (ntoks) *ntoks = 0;
return NULL;
}
// if ntoks is muted we'll allocate str_tokscount() tokens, else *ntoks
size_t _ntoks = (ntoks && *ntoks) ? *ntoks : str_tokscount(_str, delim, keepnulls);
if ( _ntoks == 0 ) { // str_tokscount() failed
goto fail_free_str;
}
// alloc the array of strings (+1 for an extra NULL sentinel)
char **toksarr = malloc( (_ntoks+1) * sizeof(*toksarr) );
if ( !toksarr ) {
goto fail_free_str;
}
// Parse str tokens and duplicate them into the array
size_t i = 0; // # of actually parsed tokens
char *tok;
while ( i < _ntoks && (tok = strsep(&_str, delim)) ) {
// if requested, skip empty tokens
if ( *tok == '\0' && !keepnulls ) {
continue;
}
// duplicate current token into the array
char *tmptok = strdup( tok );
if ( !tmptok ) {
goto fail_free_arr;
}
toksarr[i++] = tmptok;
}
toksarr[i] = NULL; // NULL sentinel
free( _str ); // release the local copy of the source-string
if (ntoks) *ntoks = i; // pass to caller the # of parsed tokens
return toksarr;
// cleanup before failing
fail_free_arr:
for (size_t idx=0; idx < i; idx++) {
free( toksarr[idx] );
}
free( toksarr );
fail_free_str:
free( _str );
if (ntoks) *ntoks = 0;
return NULL;
}
下面的方法将为您完成所有工作（内存分配、计算长度）。更多信息和说明可在此处找到- 如何使用它：
int main (int argc, char ** argv)
{
int i;
char *s = "Hello, this is a test module for the string splitting.";
int c = 0;
char **arr = NULL;
c = split(s, ' ', &arr);
printf("found %d tokens.\n", c);
for (i = 0; i < c; i++)
printf("string #%d: %s\n", i, arr[i]);
return 0;
}
int main（int argc，char**argv）
{
int i；
char*s=“您好，这是用于字符串拆分的测试模块。”；
int c=0；
字符**arr=NULL；
c=拆分、、&arr；
printf（“找到%d个令牌。\n”，c）；
对于（i=0；i#包括
#包括
#包括
#包括
/**
*在delim上拆分str并动态分配指针数组。
*
*返回错误-1时，请检查errno
*成功时返回数组的大小，在空字符串中可能为0
*如果没有发现熟食，则为1。
*
*您可以重写它以返回char**数组，如果为空
*我知道这是一个分配问题，但我在这里做了三重数组。注意
*当击中一行“foo，，bar”中的两个delim时，数组将为：
*{“foo”，NULL，bar}
*
*您需要定义像“foo”这样的尾部delim的语义，这是
*2计数数组还是1的数组？我选择第二个条目的两个计数
*设置为NULL，因为它没有值。
*修改str，以便在出现问题时复制
*/
整型拆分（字符*str，字符delim，字符***数组，整型*length）{
char*p；
字符**res；
整数计数=0；
int k=0；
p=str；
//计算字符串中delim的出现次数
while（（p=strchr（p，delim））！=NULL）{
*p=0；//Null终止除沫器。
p++；//跳过我们的新null
计数++；
}
//分配动态数组
res=calloc（1，count*sizeof（char*）；
如果（！res）返回-1；
p=str；
对于（k=0；k我认为strep
仍然是最好的工具：
while ((token = strsep(&str, ","))) my_fn(token);
这实际上是一条分割字符串的线
额外的括号是一种风格元素，表示我们有意测试赋值结果，而不是等式运算符==
要使该模式正常工作，token
和str
都具有类型char*
。如果您以字符串文字开头，则首先要复制它：
// More general pattern:
const char *my_str_literal = "JAN,FEB,MAR";
char *token, *str, *tofree;
tofree = str = strdup(my_str_literal); // We own str's memory now.
while ((token = strsep(&str, ","))) my_fn(token);
free(tofree);
如果两个分隔符同时出现在str
中，您将得到一个标记
值，该值为空字符串。str
的值会被修改，因为遇到的每个分隔符都会被零字节覆盖，这是复制首先解析的字符串的另一个很好的理由
在一篇评论中，有人建议strtok
比stresp
好，因为strtok
更便于携带。Ubuntu和Mac OS X有stresp
；可以肯定地猜测，其他unixy系统也有类似的功能。Windows缺少stresp
，但它有
void splitString(const char *original, const char *delimiter, char ** * buffer, int * numStrings, int * * stringLengths){
const int lo = strlen(original);
const int ld = strlen(delimiter);
if(ld > lo){
*buffer = (void *)0;
*numStrings = 0;
*stringLengths = (void *)0;
return;
}
*numStrings = 1;
for(int i = 0;i < (lo - ld);i++){
if(strncmp(&original[i], delimiter, ld) == 0) {
i += (ld - 1);
(*numStrings)++;
}
}
*stringLengths = (int *) malloc(sizeof(int) * *numStrings);
int currentStringLength = 0;
int currentStringNumber = 0;
int delimiterTokenDecrementCounter = 0;
for(int i = 0;i < lo;i++){
if(delimiterTokenDecrementCounter > 0){
delimiterTokenDecrementCounter--;
} else if(i < (lo - ld)){
if(strncmp(&original[i], delimiter, ld) == 0){
(*stringLengths)[currentStringNumber] = currentStringLength;
currentStringNumber++;
currentStringLength = 0;
delimiterTokenDecrementCounter = ld - 1;
} else {
currentStringLength++;
}
} else {
currentStringLength++;
}
if(i == (lo - 1)){
(*stringLengths)[currentStringNumber] = currentStringLength;
}
}
*buffer = (char **) malloc(sizeof(char *) * (*numStrings));
for(int i = 0;i < *numStrings;i++){
(*buffer)[i] = (char *) malloc(sizeof(char) * ((*stringLengths)[i] + 1));
}
currentStringNumber = 0;
currentStringLength = 0;
delimiterTokenDecrementCounter = 0;
for(int i = 0;i < lo;i++){
if(delimiterTokenDecrementCounter > 0){
delimiterTokenDecrementCounter--;
} else if(currentStringLength >= (*stringLengths)[currentStringNumber]){
(*buffer)[currentStringNumber][currentStringLength] = 0;
delimiterTokenDecrementCounter = ld - 1;
currentStringLength = 0;
currentStringNumber++;
} else {
(*buffer)[currentStringNumber][currentStringLength] = (char)original[i];
currentStringLength++;
}
}
buffer[currentStringNumber][currentStringLength] = 0;
}
int main(){
const char *string = "STRING-1 DELIM string-2 DELIM sTrInG-3";
char **buffer;
int numStrings;
int * stringLengths;
splitString(string, " DELIM ", &buffer, &numStrings, &stringLengths);
for(int i = 0;i < numStrings;i++){
printf("String: %s\n", buffer[i]);
}
}
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
char** split(char* a_str, const char a_delim, int* len){
char* s = (char*)malloc(sizeof(char) * strlen(a_str));
strcpy(s, a_str);
char* tmp = a_str;
int count = 0;
while (*tmp != '\0'){
if (*tmp == a_delim) count += 1;
tmp += 1;
}
*len = count;
char** results = (char**)malloc(count * sizeof(char*));
results[0] = s;
int i = 1;
while (*s!='\0'){
if (*s == a_delim){
*s = '\0';
s += 1;
results[i++] = s;
}
else s += 1;
}
return results;
}
if (str[i]==delim) {
char *c=delim; while(*c && *c!=str[i]) c++;
if (*c) {
#include <stdlib.h>
#include <string.h>
char **split(char *str, size_t len, char delim, char ***result, unsigned long *count, unsigned long max) {
size_t i;
char **_result;
// there is at least one string returned
*count=1;
_result= *result;
// when the result array is specified, fill it during the first pass
if (_result) {
_result[0]=str;
}
// scan the string for delimiter, up to specified length
for (i=0; i<len; ++i) {
// to compare against a list of delimiters,
// define delim as a string and replace
// the next line:
// if (str[i]==delim) {
//
// with the two following lines:
// char *c=delim; while(*c && *c!=str[i]) c++;
// if (*c) {
//
if (str[i]==delim) {
// replace delimiter with zero
str[i]=0;
// when result array is specified, fill it during the first pass
if (_result) {
_result[*count]=str+i+1;
}
// increment count for each separator found
++(*count);
// if max is specified, dont go further
if (max && *count==max) {
break;
}
}
}
// when result array is specified, we are done here
if (_result) {
return _result;
}
// else allocate memory for result
// and fill the result array
*result=malloc((*count)*sizeof(char*));
if (!*result) {
return NULL;
}
_result=*result;
// add first string to result
_result[0]=str;
// if theres more strings
for (i=1; i<*count; ++i) {
// find next string
while(*str) ++str;
++str;
// add next string to result
_result[i]=str;
}
return _result;
}
#include <stdio.h>
int main(int argc, char **argv) {
char *str="JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC";
char **result=malloc(6*sizeof(char*));
char **result2=0;
unsigned long count;
unsigned long count2;
unsigned long i;
split(strdup(str),strlen(str),',',&result,&count,6);
split(strdup(str),strlen(str),',',&result2,&count2,0);
if (result)
for (i=0; i<count; ++i) {
printf("%s\n",result[i]);
}
printf("\n");
if (result2)
for (i=0; i<count2; ++i) {
printf("%s\n", result2[i]);
}
return 0;
}
int split (const char *txt, char delim, char ***tokens)
{
int *tklen, *t, count = 1;
char **arr, *p = (char *) txt;
while (*p != '\0') if (*p++ == delim) count += 1;
t = tklen = calloc (count, sizeof (int));
for (p = (char *) txt; *p != '\0'; p++) *p == delim ? *t++ : (*t)++;
*tokens = arr = malloc (count * sizeof (char *));
t = tklen;
p = *arr++ = calloc (*(t++) + 1, sizeof (char *));
while (*txt != '\0')
{
if (*txt == delim)
{
p = *arr++ = calloc (*(t++) + 1, sizeof (char *));
txt++;
}
else *p++ = *txt++;
}
free (tklen);
return count;
}
char **tokens;
int count, i;
const char *str = "JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC";
count = split (str, ',', &tokens);
for (i = 0; i < count; i++) printf ("%s\n", tokens[i]);
/* freeing tokens */
for (i = 0; i < count; i++) free (tokens[i]);
free (tokens);
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int dtmsplit(char *str, const char *delim, char ***array, int *length ) {
int i=0;
char *token;
char **res = (char **) malloc(0 * sizeof(char *));
/* get the first token */
token = strtok(str, delim);
while( token != NULL )
{
res = (char **) realloc(res, (i + 1) * sizeof(char *));
res[i] = token;
i++;
token = strtok(NULL, delim);
}
*array = res;
*length = i;
return 1;
}
int main()
{
int i;
int c = 0;
char **arr = NULL;
int count =0;
char str[80] = "JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC";
c = dtmsplit(str, ",", &arr, &count);
printf("Found %d tokens.\n", count);
for (i = 0; i < count; i++)
printf("string #%d: %s\n", i, arr[i]);
return(0);
}
Found 12 tokens.
string #0: JAN
string #1: FEB
string #2: MAR
string #3: APR
string #4: MAY
string #5: JUN
string #6: JUL
string #7: AUG
string #8: SEP
string #9: OCT
string #10: NOV
string #11: DEC
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
typedef struct
{
uintptr_t ptr;
int size;
} token_t;
int explode(char *str, int slen, const char *delimiter, token_t **tokens)
{
int i = 0, c1 = 0, c2 = 0;
for(i = 0; i <= slen; i++)
{
if(str[i] == *delimiter)
{
c1++;
}
}
if(c1 == 0)
{
return -1;
}
*tokens = (token_t*)calloc((c1 + 1), sizeof(token_t));
((*tokens)[c2]).ptr = (uintptr_t)str;
i = 0;
while(i <= slen)
{
if((str[i] == *delimiter) || (i == slen))
{
((*tokens)[c2]).size = (int)((uintptr_t)&(str[i]) - (uintptr_t)(((*tokens)[c2]).ptr));
if(i < slen)
{
c2++;
((*tokens)[c2]).ptr = (uintptr_t)&(str[i + 1]);
}
}
i++;
}
return (c1 + 1);
}
char* implode(token_t *tokens, int size, const char *delimiter)
{
int i, len = 0;
char *str;
for(i = 0; i < len; i++)
{
len += tokens[i].size + 1;
}
str = (char*)calloc(len, sizeof(char));
len = 0;
for(i = 0; i < size; i++)
{
memcpy((void*)&str[len], (void*)tokens[i].ptr, tokens[i].size);
len += tokens[i].size;
str[(len++)] = *delimiter;
}
str[len - 1] = '\0';
return str;
}
int main(int argc, char **argv)
{
int i, c;
char *exp = "JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC";
token_t *tokens;
char *imp;
printf("%s\n", exp);
if((c = explode(exp, strlen(exp), ",", &tokens)) > 0)
{
imp = implode(tokens, c, ",");
printf("%s\n", imp);
for(i = 0; i < c; i++)
{
printf("%.*s, %d\n", tokens[i].size, (char*)tokens[i].ptr, tokens[i].size);
}
}
free((void*)tokens);
free((void*)imp);
return 0;
}
char *zstring_strtok(char *str, const char *delim) {
static char *static_str=0; /* var to store last address */
int index=0, strlength=0; /* integers for indexes */
int found = 0; /* check if delim is found */
/* delimiter cannot be NULL
* if no more char left, return NULL as well
*/
if (delim==0 || (str == 0 && static_str == 0))
return 0;
if (str == 0)
str = static_str;
/* get length of string */
while(str[strlength])
strlength++;
/* find the first occurance of delim */
for (index=0;index<strlength;index++)
if (str[index]==delim[0]) {
found=1;
break;
}
/* if delim is not contained in str, return str */
if (!found) {
static_str = 0;
return str;
}
/* check for consecutive delimiters
*if first char is delim, return delim
*/
if (str[0]==delim[0]) {
static_str = (str + 1);
return (char *)delim;
}
/* terminate the string
* this assignmetn requires char[], so str has to
* be char[] rather than *char
*/
str[index] = '\0';
/* save the rest of the string */
if ((str + index + 1)!=0)
static_str = (str + index + 1);
else
static_str = 0;
return str;
}
Example Usage
char str[] = "A,B,,,C";
printf("1 %s\n",zstring_strtok(s,","));
printf("2 %s\n",zstring_strtok(NULL,","));
printf("3 %s\n",zstring_strtok(NULL,","));
printf("4 %s\n",zstring_strtok(NULL,","));
printf("5 %s\n",zstring_strtok(NULL,","));
printf("6 %s\n",zstring_strtok(NULL,","));
Example Output
1 A
2 B
3 ,
4 ,
5 C
6 (null)
#include "bstrlib.h"
#include <stdio.h>
int main() {
int i;
char *tmp = "Hello,World,sak";
bstring bstr = bfromcstr(tmp);
struct bstrList *blist = bsplit(bstr, ',');
printf("num %d\n", blist->qty);
for(i=0;i<blist->qty;i++) {
printf("%d: %s\n", i, bstr2cstr(blist->entry[i], '_'));
}
}
typedef struct {
const char *start;
size_t len;
} token;
char **split(const char *str, char sep)
{
char **array;
unsigned int start = 0, stop, toks = 0, t;
token *tokens = malloc((strlen(str) + 1) * sizeof(token));
for (stop = 0; str[stop]; stop++) {
if (str[stop] == sep) {
tokens[toks].start = str + start;
tokens[toks].len = stop - start;
toks++;
start = stop + 1;
}
}
/* Mop up the last token */
tokens[toks].start = str + start;
tokens[toks].len = stop - start;
toks++;
array = malloc((toks + 1) * sizeof(char*));
for (t = 0; t < toks; t++) {
/* Calloc makes it nul-terminated */
char *token = calloc(tokens[t].len + 1, 1);
memcpy(token, tokens[t].start, tokens[t].len);
array[t] = token;
}
/* Add a sentinel */
array[t] = NULL;
free(tokens);
return array;
}
int split(char* str, const char delimeter, char*** args) {
int cnt = 1;
char* t = str;
while (*t == delimeter) t++;
char* t2 = t;
while (*(t2++))
if (*t2 == delimeter && *(t2 + 1) != delimeter && *(t2 + 1) != 0) cnt++;
(*args) = malloc(sizeof(char*) * cnt);
for(int i = 0; i < cnt; i++) {
char* ts = t;
while (*t != delimeter && *t != 0) t++;
int len = (t - ts + 1);
(*args)[i] = malloc(sizeof(char) * len);
memcpy((*args)[i], ts, sizeof(char) * (len - 1));
(*args)[i][len - 1] = 0;
while (*t == delimeter) t++;
}
return cnt;
}
#include <stdio.h>
#include <string.h>
struct splitFieldType {
char *field;
int maxLength;
};
typedef struct splitFieldType splitField;
int strsplit(splitField *fields, int expected, const char *input, const char *fieldSeparator, void (*softError)(int fieldNumber,int expected,int actual)) {
int i;
int fieldSeparatorLen=strlen(fieldSeparator);
const char *tNext, *tLast=input;
for (i=0; i<expected && (tNext=strstr(tLast, fieldSeparator))!=NULL; ++i) {
int len=tNext-tLast;
if (len>=fields[i].maxLength) {
softError(i,fields[i].maxLength-1,len);
len=fields[i].maxLength-1;
}
fields[i].field[len]=0;
strncpy(fields[i].field,tLast,len);
tLast=tNext+fieldSeparatorLen;
}
if (i<expected) {
if (strlen(tLast)>fields[i].maxLength) {
softError(i,fields[i].maxLength,strlen(tLast));
} else {
strcpy(fields[i].field,tLast);
}
return i+1;
} else {
return i;
}
}
void monthSplitSoftError(int fieldNumber, int expected, int actual) {
fprintf(stderr,"monthSplit: input field #%d is %d bytes, expected %d bytes\n",fieldNumber+1,actual,expected);
}
int main() {
const char *fieldSeparator=",";
const char *input="JAN,FEB,MAR,APRI,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC,FOO,BAR";
struct monthFieldsType {
char field1[4];
char field2[4];
char field3[4];
char field4[4];
char field5[4];
char field6[4];
char field7[4];
char field8[4];
char field9[4];
char field10[4];
char field11[4];
char field12[4];
} monthFields;
splitField inputFields[12] = {
{monthFields.field1, sizeof(monthFields.field1)},
{monthFields.field2, sizeof(monthFields.field2)},
{monthFields.field3, sizeof(monthFields.field3)},
{monthFields.field4, sizeof(monthFields.field4)},
{monthFields.field5, sizeof(monthFields.field5)},
{monthFields.field6, sizeof(monthFields.field6)},
{monthFields.field7, sizeof(monthFields.field7)},
{monthFields.field8, sizeof(monthFields.field8)},
{monthFields.field9, sizeof(monthFields.field9)},
{monthFields.field10, sizeof(monthFields.field10)},
{monthFields.field11, sizeof(monthFields.field11)},
{monthFields.field12, sizeof(monthFields.field12)}
};
int expected=sizeof(inputFields)/sizeof(splitField);
printf("input data: %s\n", input);
printf("expecting %d fields\n",expected);
int ct=strsplit(inputFields, expected, input, fieldSeparator, monthSplitSoftError);
if (ct!=expected) {
printf("string split %d fields, expected %d\n", ct,expected);
}
for (int i=0;i<expected;++i) {
printf("field %d: %s\n",i+1,inputFields[i].field);
}
printf("\n");
printf("Direct structure access, field 10: %s", monthFields.field10);
}
$ gcc strsplitExample.c && ./a.out
input data: JAN,FEB,MAR,APRIL,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC,FOO,BAR
expecting 12 fields
monthSplit: input field #4 is 5 bytes, expected 3 bytes
field 1: JAN
field 2: FEB
field 3: MAR
field 4: APR
field 5: MAY
field 6: JUN
field 7: JUL
field 8: AUG
field 9: SEP
field 10: OCT
field 11: NOV
field 12: DEC
Direct structure access, field 10: OCT
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define NPTRS 2 /* initial number of pointers to allocate (must be > 0) */
/* split src into tokens with sentinel NULL after last token.
* return allocated pointer-to-pointer with sentinel NULL on success,
* or NULL on failure to allocate initial block of pointers. The number
* of allocated pointers are doubled each time reallocation required.
*/
char **strsplit (const char *src, const char *delim)
{
int i = 0, in = 0, nptrs = NPTRS; /* index, in/out flag, ptr count */
char **dest = NULL; /* ptr-to-ptr to allocate/fill */
const char *p = src, *ep = p; /* pointer and end-pointer */
/* allocate/validate nptrs pointers for dest */
if (!(dest = malloc (nptrs * sizeof *dest))) {
perror ("malloc-dest");
return NULL;
}
*dest = NULL; /* set first pointer as sentinel NULL */
for (;;) { /* loop continually until end of src reached */
if (!*ep || strchr (delim, *ep)) { /* if at nul-char or delimiter char */
size_t len = ep - p; /* get length of token */
if (in && len) { /* in-word and chars in token */
if (i == nptrs - 1) { /* used pointer == allocated - 1? */
/* realloc dest to temporary pointer/validate */
void *tmp = realloc (dest, 2 * nptrs * sizeof *dest);
if (!tmp) {
perror ("realloc-dest");
break; /* don't exit, original dest still valid */
}
dest = tmp; /* assign reallocated block to dest */
nptrs *= 2; /* increment allocated pointer count */
}
/* allocate/validate storage for token */
if (!(dest[i] = malloc (len + 1))) {
perror ("malloc-dest[i]");
break;
}
memcpy (dest[i], p, len); /* copy len chars to storage */
dest[i++][len] = 0; /* nul-terminate, advance index */
dest[i] = NULL; /* set next pointer NULL */
}
if (!*ep) /* if at end, break */
break;
in = 0; /* set in-word flag 0 (false) */
}
else { /* normal word char */
if (!in) /* if not in-word */
p = ep; /* update start to end-pointer */
in = 1; /* set in-word flag 1 (true) */
}
ep++; /* advance to next character */
}
return dest;
}
int main (void) {
char *str = "JAN,FEB,MAR,APR,MAY,,,JUN,JUL,AUG,SEP,OCT,NOV,DEC",
**tokens; /* pointer to pointer to char */
if ((tokens = strsplit (str, ","))) { /* split string into tokens */
for (char **p = tokens; *p; p++) { /* loop over filled pointers */
puts (*p);
free (*p); /* don't forget to free allocated strings */
}
free (tokens); /* and pointers */
}
}
$ ./bin/splitinput
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <stdbool.h> // C99
// tokenize destructively
char **str_toksarray_alloc(
char **strp, /* InOut: pointer to the source non-constant c-string */
const char *delim, /* c-string containing the delimiting chars */
size_t *ntoks, /* InOut: # of tokens to parse/parsed (NULL or *ntoks==0 for all tokens) */
bool keepnulls /* false ignores empty tokens, true includes them */
);
// tokenize non-destructively
char **str_toksarray_alloc2(
const char *str, /* the source c-string */
const char *delim,
size_t *ntoks,
bool keepnulls
);
const char *src = ";b,test,Tèst,;;cd;ελληνικά,nørmälize,;string ｔｏ";
const char *delim = ";,";
bool keepnulls = true;
size_t ntoks = 0;
// destructive (use copy of src)
char *scopy = strdup( src );
if (!scopy) { ... }; // handle strdup failure
printf( "%s\n", src );
char **arrtoks = str_toksarray_alloc( &scopy, delim, &ntoks, keepnulls );
printf( "%lu tokens read\n", ntoks );
if ( arrtoks ) {
for (int i=0; arrtoks[i]; i++) {
printf( "%d: %s\n", i, arrtoks[i] );
}
}
free( scopy );
free( arrtoks );
/* OUTPUT
;b,test,Tèst,;;cd;ελληνικά,nørmälize,;string ｔｏ
11 tokens read
0:
1: b
2: test
3: Tèst
4:
5:
6: cd
7: ελληνικά
8: nørmälize
9:
10: string ｔｏ
*/
// non-destructive
keepnulls = false; // reject empty tokens
printf( "%s\n", src );
arrtoks = str_toksarray_alloc2( src, delim, &ntoks, keepnulls );
printf( "%lu tokens read\n", ntoks );
if ( arrtoks ) {
for (int i=0; arrtoks[i]; i++) {
printf( "%d: %s\n", i, arrtoks[i] );
}
}
toksarray_free2( arrtoks ); // dangling arrtoks
// or: arrtoks = toksarray_free2( arrtoks ); // non-dangling artoks
/* OUTPUT
;b,test,Tèst,;;cd;ελληνικά,nørmälize,;string ｔｏ
7 tokens read
0: b
1: test
2: Tèst
3: cd
4: ελληνικά
5: nørmälize
6: string ｔｏ
*/
// ----------------------------------------
// Tokenize destructively a nul-terminated source-string.
// Return a dynamically allocated, NULL terminated array of char-pointers
// each pointing to each token found in the source-string, or NULL on error.
//
char **str_toksarray_alloc(char **strp, const char *delim, size_t *ntoks, bool keepnulls)
{
// sanity checks
if ( !strp || !*strp || !**strp || !delim ) {
goto failed;
}
char *strpSaved = *strp; // save initial *strp pointer
bool ntoksOk = (ntoks && *ntoks); // false when ntoks is muted
size_t _ntoks = (ntoksOk ? *ntoks : 16); // # of tokens to alloc-ahead
// alloc array of char-pointers (+1 for NULL sentinel)
char **toksarr = malloc( (_ntoks+1) * sizeof(*toksarr) );
if ( !toksarr ) {
goto failed;
}
// Parse *strp tokens into the array
size_t i = 0; // # of actually parsed tokens
char *tok;
while ( (tok = strsep(strp, delim)) ) {
// if requested, ignore empty tokens
if ( *tok == '\0' && !keepnulls ) {
continue;
}
// non-muted ntoks reached? we are done
if ( ntoksOk && i == _ntoks ) {
*ntoks = i;
break;
}
// muted ntoks & ran out of space? double toksarr and keep parsing
if ( !ntoksOk && i == _ntoks ) {
_ntoks *= 2;
char **tmparr = realloc( toksarr, (_ntoks+1) * sizeof(*tmparr) );
if ( !tmparr ) {
*strp = strpSaved;
free( toksarr );
goto failed;
}
toksarr = tmparr;
}
toksarr[i++] = tok; // get token address
}
toksarr[i] = NULL; // NULL sentinel
*strp = strpSaved; // restore initial *strp pointer
if (ntoks) *ntoks = i; // pass to caller # of parsed tokens
return toksarr;
failed:
if (ntoks) *ntoks = 0;
return NULL;
}
// ----------------------------------------
// Tokenize non-destructively a nul-terminated source-string.
// Return a dynamically allocated, NULL terminated array of dynamically
// allocated and nul-terminated string copies of each token found in the
// source-string. Return NULL on error.
// The 2 at the end of the name means 2-levels of allocation.
//
char **str_toksarray_alloc2( const char *str, const char *delim, size_t *ntoks, bool keepnulls )
{
// sanity checks
if ( !str || !*str || !delim ) {
if (ntoks) *ntoks = 0;
return NULL;
}
// make a copy of str to work with
char *_str = strdup( str );
if ( !_str ) {
if (ntoks) *ntoks = 0;
return NULL;
}
// if ntoks is muted we'll allocate str_tokscount() tokens, else *ntoks
size_t _ntoks = (ntoks && *ntoks) ? *ntoks : str_tokscount(_str, delim, keepnulls);
if ( _ntoks == 0 ) { // str_tokscount() failed
goto fail_free_str;
}
// alloc the array of strings (+1 for an extra NULL sentinel)
char **toksarr = malloc( (_ntoks+1) * sizeof(*toksarr) );
if ( !toksarr ) {
goto fail_free_str;
}
// Parse str tokens and duplicate them into the array
size_t i = 0; // # of actually parsed tokens
char *tok;
while ( i < _ntoks && (tok = strsep(&_str, delim)) ) {
// if requested, skip empty tokens
if ( *tok == '\0' && !keepnulls ) {
continue;
}
// duplicate current token into the array
char *tmptok = strdup( tok );
if ( !tmptok ) {
goto fail_free_arr;
}
toksarr[i++] = tmptok;
}
toksarr[i] = NULL; // NULL sentinel
free( _str ); // release the local copy of the source-string
if (ntoks) *ntoks = i; // pass to caller the # of parsed tokens
return toksarr;
// cleanup before failing
fail_free_arr:
for (size_t idx=0; idx < i; idx++) {
free( toksarr[idx] );
}
free( toksarr );
fail_free_str:
free( _str );
if (ntoks) *ntoks = 0;
return NULL;
}
// ----------------------------------------
// Return the count of tokens present in a nul-terminated source-string (str),
// based on the delimiting chars contained in a 2nd nul-terminated string (delim).
// If the boolean argument is false, empty tokens are excluded.
//
// To stay consistent with the behavior of strsep(), the function returns 1 if
// delim is an empty string or none of its delimiters is found in str (in those
// cases the source-string is considered a single token).
// 0 is returned when str or delim are passed as NULL pointers, or when str is
// passed as an empty string.
//
size_t str_tokscount( const char *str, const char *delim, bool keepnulls )
{
// sanity checks
if ( !str || !*str || !delim ) {
return 0;
}
const char *tok = str;
size_t nnulls = strchr(delim, *str) ? 1 : 0;
size_t ntoks = 1; // even when no delims in str, str counts as 1 token
for (; (str = strpbrk(tok, delim)); ntoks++ ) {
tok = ++str;
if ( strchr(delim, *str) ) {
nnulls++;
}
}
return keepnulls ? ntoks : (ntoks - nnulls);
}
// ----------------------------------------
// Free a dynamically allocated, NULL terminated, array of char-pointers
// with each such pointer pointing to its own dynamically allocated data.
// Return NULL, so the caller has the choice of assigning it back to the
// dangling pointer. The 2 at the end of the name means 2-levels of deallocation.
//
// NULL terminated array means ending with a NULL sentinel.
// e.g.: toksarr[0] = tok1, ..., toksarr[len] = NULL
//
char **toksarray_free2( char **toksarr )
{
if ( toksarr ) {
char **toks = toksarr;
while ( *toks ) { // walk until NULL sentinel
free( *toks++ );
}
free( toksarr );
}
return NULL;
}