指定した文字数だけ、文字列をコピー

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指定した文字数だけ、文字列をコピー

C

#include <stdio.h>

#include <string.h>
char* str_ncpy(char* d, const char* s, size_t n)

{

    char* t = d;
    int j = 1;

    unsigned i;

    for (i = 0; i < n; i++)

    {

        if ((*s) && j)

            *d++ = *s++;

        else

        {

            j = 0;

            *d++ = '\0'; /* \0 で 埋める */

        }

    }
    return t;

}
int main(int argc, char* argv[])

{

    int i;

    char* st1 = "1234567890";

    char* st2 = "ABCDE";
    printf("st1 = %s\n", st1);

    printf("st2 = %s\n", st2);

    puts("");
    str_ncpy(st1, st2, 4);

    printf("st1 = %s\n", st1);

    printf("st2 = %s\n", st2);

    puts("");
    str_ncpy(st1, st2, 6);

    printf("st1 = ");

    for (i = 0; i < 10; i++)

        if (st1[i] == '\0')

            putchar(' ');

        else

            putchar(st1[i]);

    putchar('\n');

    printf("st2 = %s\n", st2);

    puts("");
    st1 = "1234567890";

    strncpy(st1, st2, 4);

    printf("st1 = %s\n", st1);

    printf("st2 = %s\n", st2);

    puts("");
    strncpy(st1, st2, 6);

    printf("st1 = ");

    for (i = 0; i < 10; i++)

        if (st1[i] == '\0')

            putchar(' ');

        else

            putchar(st1[i]);

    putchar('\n');

    printf("st2 = %s\n", st2);

    puts("");
    return 0;

}

実行結果

R:\>lesson086\project1.exe

st1 = 1234567890

st2 = ABCDE
st1 = ABCD567890

st2 = ABCDE
st1 = ABCDE 7890

st2 = ABCDE
st1 = ABCD567890

st2 = ABCDE
st1 = ABCDE 7890

st2 = ABCDE

Delphi

program Project1;
{$APPTYPE CONSOLE}
uses

    SysUtils;
function str_ncpy(d:PChar; s:PChar; n:Integer):PChar;

var

    i, j: Integer;

begin

    result := d;
    j:= 1;

    for i := 0 to n - 1 do

    begin

        if s^ <> #0 then

        begin

            d^ := s^;

            Inc(s);

            Inc(d);

        end

        else

        begin

            d^ := #0;

            j  := 0;

            break;

        end;

    end;
    if j = 1 then

        d^ := #0;

end;
procedure main();

const

    st1: String                = '1234567890';

    st2: String                = 'ABCDE';
    pt1: array[0..255] of Char = '1234567890';

    pt2: array[0..255] of Char = 'ABCDE';

var

    i: Integer;

begin

    Writeln(Format('st1 = %s', [st1]));

    Writeln(Format('st2 = %s', [st2]));

    Writeln('');
    st1 := Copy(st2, 1, 4);

    Writeln(Format('st1 = %s', [st1]));

    Writeln(Format('st2 = %s', [st2]));

    Writeln('');
    st1 := '1234567890';

    st1 := Copy(st2, 1, 6);

    Writeln(Format('st1 = %s', [st1]));

    Writeln(Format('st2 = %s', [st2]));

    Writeln('');




    Writeln(Format('pt1 = %s', [pt1]));

    Writeln(Format('pt2 = %s', [pt2]));

    Writeln('');
    str_ncpy(pt1, pt2, 4);

    write('pt1 = ');

    for i := 0 to 9 do

        if pt1[i] = #0 then

            write(' ')

        else

            write(pt1[i]);

    Writeln('');

    Writeln(Format('pt2 = %s', [pt2]));

    Writeln('');
    pt1 := '1234567890';

    str_ncpy(pt1, pt2, 6);

    write('pt1 = ');

    for i := 0 to 9 do

        if pt1[i] = #0 then

            write(' ')

        else

            write(pt1[i]);

    Writeln('');

    Writeln(Format('pt2 = %s', [pt2]));

    Writeln('');




    pt1 := '1234567890';

    StrLCopy(pt1, pt2, 4);

    write('pt1 = ');

    for i := 0 to 9 do

        if pt1[i] = #0 then

            write(' ')

        else

            write(pt1[i]);

    Writeln('');

    Writeln(Format('pt2 = %s', [pt2]));

    Writeln('');
    pt1 := '1234567890';

    StrLCopy(pt1, pt2, 6);

    write('pt1 = ');

    for i := 0 to 9 do

        if pt1[i] = #0 then

            write(' ')

        else

            write(pt1[i]);

    Writeln('');

    Writeln(Format('pt2 = %s', [pt2]));

    Writeln('');




    pt1 := '1234567890';

    StrMove(pt1, pt2, 4);

    write('pt1 = ');

    for i := 0 to 9 do

        if pt1[i] = #0 then

            write(' ')

        else

            write(pt1[i]);

    Writeln('');

    Writeln(Format('pt2 = %s', [pt2]));

    Writeln('');
    pt1 := '1234567890';

    StrMove(pt1, pt2, 6);

    write('pt1 = ');

    for i := 0 to 9 do

        if pt1[i] = #0 then

            write(' ')

        else

            write(pt1[i]);

    Writeln('');

    Writeln(Format('pt2 = %s', [pt2]));

    Writeln('');

end;
begin

    main;

end.

実行結果

S:\>lesson086\project1.exe

st1 = 1234567890

st2 = ABCDE
st1 = ABCD

st2 = ABCDE
st1 = ABCDE

st2 = ABCDE
pt1 = 1234567890

pt2 = ABCDE
pt1 = ABCD 67890

pt2 = ABCDE
pt1 = ABCDE 7890

pt2 = ABCDE
pt1 = ABCD 67890

pt2 = ABCDE
pt1 = ABCDE 7890

pt2 = ABCDE
pt1 = ABCD567890

pt2 = ABCDE
pt1 = ABCDE 7890

pt2 = ABCDE