《c程序设计语言》读书笔记-5.6-指针重写getline等函数

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#include <stdio.h>#include <math.h>#include <stdlib.h>#include <string.h>#include <ctype.h>#include <curses.h>int getline_(char *s,int n){    char c;    char *sta = s;    while(--n > 0 && (c = getchar()) != EOF && c != '\n')    {        *s++ = c;    }    if(c == '\n')        *s++ = c;    *s = '\0';    return s - sta;}int atoi_(char *s){    int n,sign;    for(;isspace(*s);s++)        ;    sign = (*s == '-') ? -1 : 1;    if(*s == '+' || *s == '-')        s++;    for(n = 0;isdigit(*s);s++)        n = 10 * n + *s - '0';    return sign * n;}void reverse_(char *s){    int temp;    char *t;    for(t = s + strlen(s) - 1;s < t;s++,t--)    {        temp = *s;        *s = *t;        *t = temp;    }}void itoa_(int n,char *s){    int sign;    char *t = s;    if((sign = n) < 0)        n = -n;    do    {        *s++ = n % 10 + '0';    }while((n /= 10) != 0);    if(sign < 0)        *s++ ='-';    *s = '\0';    reverse_(t);}int strindex_(char *s,char *t)   //返回最右边出现的位置{    char *sta = s;    char *p,*r;    int n = -2;    for(;*s != '\0';s++)    {        for(p = s,r = t;*r != '\0' && *p == *r;p++,r++)            ;        if(r > t && *r == '\0')            n =  s - sta;    }    if(n != -2)        return n;    else        return -1;}int main(){    char p[] = "abcdefgab",q[] = "uh";    int n;    n = strindex_(p,q);    printf("%d",n);    return 0;}

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