C 掙扎於 getline() - 不兼容的 integer 到指針轉換

Question

我需要我的程序收集隨機用戶輸入，以便將字符數返回為奇數或偶數（ return ( strlen ( &raw_scrap ) % 2 ); ）

我無法讓getline() function 從char raw_scrap全局聲明中正常工作。

以下是我收到的警告：

$clang geomant.c -o geomant.bin
geomant.c:61:12: warning: incompatible integer to pointer conversion passing 'char' to parameter of type 'char **' [-Wint-conversion]
        getline ( raw_scrap, sizeof(&raw_scrap), stdin ) ;
                  ^~~~~~~~~
/usr/include/stdio.h:239:36: note: passing argument to parameter here
ssize_t  getline(char ** __restrict, size_t * __restrict,
                                   ^
geomant.c:61:23: warning: incompatible integer to pointer conversion passing 'unsigned long' to parameter of type 'size_t *' (aka 'unsigned long *') [-Wint-conversion]
        getline ( raw_scrap, sizeof(&raw_scrap), stdin ) ;
                             ^~~~~~~~~~~~~~~~~~
/usr/include/stdio.h:239:57: note: passing argument to parameter here
ssize_t  getline(char ** __restrict, size_t * __restrict,
                                                        ^
2 warnings generated.

這是我的完整代碼（為了緊湊/可讀性，省略重復的 arrays）：

/*****************************************/
/*     Geomant : a basic implementation  */
/*  of the geomanteia intended as a first*/
/*  C training project                   */
/*  copyright \xc2\xa9 Sylvain Saboua    */
/*  <sylvain ! saboua (|) free ! fr>     */
/*****************************************/

# include <stdlib.h>
# include <stdio.h>
# include <string.h>
# include <unistd.h>

char *body_parts[] = { "head", "neck", "body", "legs" } ;
char *mother_figures[] = { "1st", "2nd", "3rd", "4th" } ;

int n_figure ;
int n_bodypart ;

char raw_scrap ;
char *figures[15][4] = {
        // mothers
        {"* *", "* *", "* *", "* *"},
        {"* *", "* *", "* *", "* *"},
        {"* *", "* *", "* *", "* *"},
        {"* *", "* *", "* *", "* *"},

        // daughters
        {"* *", "* *", "* *", "* *"},
        {"* *", "* *", "* *", "* *"},
        {"* *", "* *", "* *", "* *"},
        {"* *", "* *", "* *", "* *"},

        // nieces
        {"* *", "* *", "* *", "* *"},
        {"* *", "* *", "* *", "* *"},
        {"* *", "* *", "* *", "* *"},
        {"* *", "* *", "* *", "* *"},

        // witnesses & judge
        {"* *", "* *", "* *", "* *"},
        {"* *", "* *", "* *", "* *"},
        {"* *", "* *", "* *", "* *"}
} ;

/*

        "mantize" : input fuction

 This function gathers a string of user input
 and returns a 0 or 1 for the evenness or
 oddity of the number of characters. It is called
 in a sequence by the next function to generate
 the figures one by one.

*/

int mantize ( int n_bodypart, int n_figure ) {
        printf ( "Hold or repeatedly press a key or keys to generate the %s of the %s mother
, then press Enter:\n",
                body_parts[n_bodypart], mother_figures[n_figure] ) ;
        getline ( raw_scrap, sizeof(&raw_scrap), stdin ) ;
        return ( strlen ( &raw_scrap ) % 2 ) ;
}

/*

        "generate" fuction:

 This function takes the cast result (being 0 or 1,
 odd or even) and use it to generate
 all 15 figures, from the mothers down to the
 daughters, nieces, witnesses and judge.

*/

int generate(){

        // generating the mothers

        for ( n_figure = 0 ; n_figure < 4 ; n_figure++ ) {
                for ( n_bodypart = 0 ; n_bodypart < 4 ; n_bodypart++ ) {
                        figures[n_figure][n_bodypart] =
                        (0 == mantize(n_bodypart, n_figure)) ? "* *" : "*" ;
                }
        }

        //generating the four daughters from the four mothers

        figures[4][0] = figures[0][0] ;
        figures[4][1] = figures[1][0] ;
        figures[4][2] = figures[2][0] ;
        figures[4][3] = figures[3][0] ;

        figures[5][0] = figures[0][1] ;
        figures[5][1] = figures[1][1] ;
        figures[5][2] = figures[2][1] ;
        figures[5][3] = figures[3][1] ;

        figures[6][0] = figures[0][2] ;
        figures[6][1] = figures[1][2] ;
        figures[6][2] = figures[2][2] ;
        figures[6][3] = figures[3][2] ;

        figures[7][0] = figures[0][3] ;
        figures[7][1] = figures[1][3] ;
        figures[7][2] = figures[2][3] ;
        figures[7][3] = figures[3][3] ;

        // generating the nieces

        figures[8][0] = ( figures[0][0] == figures[1][0] ) ? "* *" : " * " ;
        figures[8][1] = ( figures[0][1] == figures[1][1] ) ? "* *" : " * " ;
        figures[8][2] = ( figures[0][2] == figures[1][2] ) ? "* *" : " * " ;
        figures[8][3] = ( figures[0][3] == figures[1][3] ) ? "* *" : " * " ;

        figures[9][0] = ( figures[2][0] == figures[3][0] ) ? "* *" : " * " ;
        figures[9][1] = ( figures[2][1] == figures[3][1] ) ? "* *" : " * " ;
        figures[9][2] = ( figures[2][2] == figures[3][2] ) ? "* *" : " * " ;
        figures[9][3] = ( figures[2][3] == figures[3][3] ) ? "* *" : " * " ;

        figures[10][0] = ( figures[4][0] == figures[5][0] ) ? "* *" : " * " ;
        figures[10][1] = ( figures[4][1] == figures[5][1] ) ? "* *" : " * " ;
        figures[10][2] = ( figures[4][2] == figures[5][2] ) ? "* *" : " * " ;
        figures[10][3] = ( figures[4][3] == figures[5][3] ) ? "* *" : " * " ;

        figures[11][0] = ( figures[6][0] == figures[7][0] ) ? "* *" : " * " ;
        figures[11][1] = ( figures[6][1] == figures[7][1] ) ? "* *" : " * " ;
        figures[11][2] = ( figures[6][2] == figures[7][2] ) ? "* *" : " * " ;
        figures[11][3] = ( figures[6][3] == figures[7][3] ) ? "* *" : " * " ;

        // generating the witnesses

        figures[12][0] = ( figures[8][0] == figures[9][0] ) ? "* *" : " * " ;
        figures[12][1] = ( figures[8][1] == figures[9][1] ) ? "* *" : " * " ;
        figures[12][2] = ( figures[8][2] == figures[9][2] ) ? "* *" : " * " ;
        figures[12][3] = ( figures[8][3] == figures[9][3] ) ? "* *" : " * " ;

        figures[13][0] = ( figures[10][0] == figures[11][0] ) ? "* *" : " * " ;
        figures[13][1] = ( figures[10][1] == figures[11][1] ) ? "* *" : " * " ;
        figures[13][2] = ( figures[10][2] == figures[11][2] ) ? "* *" : " * " ;
        figures[13][3] = ( figures[10][3] == figures[11][3] ) ? "* *" : " * " ;

        //generating the judge

        figures[14][0] = ( figures[12][0] == figures[13][0] ) ? "* *" : " * " ;
        figures[14][1] = ( figures[12][1] == figures[13][1] ) ? "* *" : " * " ;
        figures[14][2] = ( figures[12][2] == figures[13][2] ) ? "* *" : " * " ;
        figures[14][3] = ( figures[12][3] == figures[13][3] ) ? "* *" : " * " ;

        return *figures[14][3] ;

}


/*

        "display" function:

 This function will display onscreen the final
 geomantic Shield for the given divination.
 The "-" & "|" characters are used for separation
 while the dots are displayed using "*"

*/
int main(){

        generate();

        //printf(*figures);

        /*
        printf(" --- ")
        for i in .*
        return(*raw_scrap[3][3]);
        */

}

Answer 1

您在濫用getline() 。 您將char值作為getline()的第一個參數傳遞，而不是所需的char ** pointer-to-pointer-to- char 。

根據POSIX getline()文檔（特別注意描述部分的粗體第二段）：

概要

#include <stdio.h> ssize_t getdelim(char **restrict lineptr, size_t *restrict n, int delimiter, FILE *restrict stream); ssize_t getline(char **restrict lineptr, size_t *restrict n, FILE *restrict stream);

描述

getdelim() function 應從 stream 讀取，直到遇到與分隔符匹配的字符。 delimiter 參數是一個int ，應用程序應確保其值是一個可表示為終止讀取過程的等值unsigned char的字符。 如果 delimiter 參數具有任何其他值，則行為未定義。

應用程序應確保*lineptr是可以傳遞給free() function 的有效參數。 如果*n不為零，則應用程序應確保*lineptr指向大小至少為*n字節的 object，或者是null指針。

If *lineptr is a null pointer or if the object pointed to by *lineptr is of insufficient size, an object shall be allocated as if by malloc() or the object shall be reallocated as if by realloc() , respectively, such that the object 足夠大以容納要寫入其中的字符，包括終止NUL ，並且*n應設置為新大小。 如果分配了 object，或者如果重新分配操作移動了 object，則*lineptr應更新為指向新的 object 或新位置。 讀取的字符（包括任何分隔符）應存儲在 object 中，並在遇到分隔符或文件結尾時添加終止NUL 。

getline() function 應等效於getdelim() function，分隔符字符等於<newline>字符。

正確使用getline()看起來更像這樣：

char *raw_scrap = NULL;
size_t raw_scrap_size = 0UL;
   .
   .
   .
        getline ( &raw_scrap, &raw_scrap_size, stdin ) ;

getline()讀取整行輸入-您必須更改程序以使用行，而不是單個char輸入。

請注意， raw_scrap必須是指向char的指針，並且該指針的地址必須傳遞給getline() ，第二個參數是實際size_t變量的地址，而不是調用sizeof()的常量結果，這不是一個地址。

另請注意，這些 arguments 中包含的值必須符合 POSIX 標准中注明的限制。