090908c語言學習日記（11章）

//修改一個字符串 #include<stdio.h> #include<string.h> #include<ctype.h> #define LIMIT 80 void Toupper(char *); int punctcount(const char *); int main(void) { char line[LIMIT]; puts("Please enter a line:"); gets(line); Toupper(line); puts(line); printf("That line has %d punctuation characters./n", punctcount(line)); getch(); return 0; } void Toupper(char *str) { while(*str)//直到遇到空字符，空字符編碼爲0，退出循環 { *str=toupper(*str);//改變爲大寫 str++; } } int punctcount(const char *str) { int ct=0; while(*str) { if(ispunct(*str))//計算標點符號 ct++; str++; } return ct; }

 

//帶有參數的main（）函數 #include<stdio.h> int main(int argc,char *argv[]) { int count; printf("The command line has %d arguments:/n",argc-1); for(count=1;count<argc;count++) { printf("%d:%s/n",count,argv[count]); } printf("/n"); getch(); return 0; }

 

D:/>cpp1.exe % fuss -r Ginger
The command line has 4 arguments:
1:%
2:fuss
3:-r
4:Ginger

D:/>

//把命令行參數轉換爲數字 #include<stdio.h> #include<stdlib.h> int main(int argc,char *argv[]) { int i,times; if(argc<2||(times=atoi(argv[1]))<1) printf("Usage:%s positive-number/n",argv[0]); else for(i=0;i<times;i++) puts("Hello,good looking!"); return 0; }

D:/>c.exe 2
Hello,good looking!
Hello,good looking!

D:/>c.exe 1
Hello,good looking!

D:/>c.exe 0
Usage:c.exe positive-number

D:/>c.exe 4ee
Hello,good looking!
Hello,good looking!
Hello,good looking!
Hello,good looking!

D:/>c.exe hh
Usage:c.exe positive-number

D:/>c.exe h12
Usage:c.exe positive-number
//strol（）函數 #include<stdio.h> #include<stdlib.h> int main(void) { char number[30]; char *end; long value; puts("Enter a number(empty line to quit.):"); while(gets(number)&&number[0]!='/0') { value=strtol(number,&end,10); printf("value;%ld,stopped at %s(%d)/n", value,end,*end); value=strtol(number,&end,16); printf("value:%ld,stopped at %s(%d)/n", value,end,*end); puts("Next number:"); } puts("Bye!/n"); getch(); return 0; }

 

Enter a number(empty line to qui
10
value;10,stopped at (0)
value:16,stopped at (0)
Next number:
2ad
value;2,stopped at ad(97)
value:685,stopped at (0)
Next number:
10atom
value;10,stopped at atom(97)
value:266,stopped at tom(116)
Next number:
0
value;0,stopped at (0)
value:0,stopped at (0)
Next number:
16
value;16,stopped at (0)
value:22,stopped at (0)
Next number:
ewqe
value;0,stopped at ewqe(101)
value:14,stopped at wqe(119)

#include<stdio.h> #include<string.h> int main(void) { char food[]={"Yummy"}; char *ptr; ptr=food+strlen(food); while((--ptr)>=food) { puts(ptr); } getch(); return 0; }

 

        y
my
mmy
ummy
Yummy

#include<stdio.h> int main(void) { char str1[]="gawsie"; char str2[]="bletonism"; char *ps; int i=0; for(ps=str1;*ps!='/0';ps++) { if(*ps=='a'||*ps=='e') putchar(*ps); else (*ps)--; putchar(*ps); } putchar('/n'); while(str2[i]!='/0') { printf("%c",i%3?str2[i]:'*'); i++; } getch(); return 0; }

#include<stdio.h> #define SIZE 81 char *strget(char *str,int n); int main(void) { char n[SIZE]; char *chk; chk=strget(n,SIZE-1); if(chk==NULL) puts("Input failed"); else puts(n); puts("Done!"); getch(); return 0; } char *strget(char *str,int n) { int i; int ch; for(i=0;i<n;i++) { ch=getchar(); if(ch!=EOF) str[i]=ch; else break; } if(ch==EOF) return NULL; else { str[i]='/0'; return str; } }

 

#include<stdio.h> char *strget(char *str,int n); int main(void) { const int N=41; char str[N]; char *ch; ch=strget(str,N-1); if(ch==NULL) puts("Input failed"); else puts(str); puts("Done!"); getch(); return 0; } char *strget(char *str,int n) { int i; int ch; for(i=0;i<n;i++) { ch=getchar(); if(ch==' '||ch=='/t'||ch=='/n') break; if(ch!=EOF) str[i]=ch; else break; } if(ch==EOF) return NULL; else { str[i]='/0'; return str; } }

#include<stdio.h> char *strget(char *,int n); int main(void) { const int SIZE=31; char str[SIZE]; char *chk; chk=strget(str,SIZE-1); if(chk==NULL) puts("Input failed"); else puts(str); puts("Done!"); getch(); return 0; } char *strget(char *str,int n) { int i; int ch; for(i=0;i<n;i++) { ch=getchar(); if(ch==' '||ch=='/n'||ch=='/t'||ch==EOF) break; else str[i]=ch; } if(ch==EOF) return NULL; else { str[i]='/0'; return str; } }