#include <stdlib.h>#include <stdio.h>int main( void ){ unsigned long lnumber = 3123456789L; char string[25]; ultoa(lnumber,string,10); printf("string = %s unsigned long = %lu\n",string,lnumber); return 0;}#include <stdio.h>#include <ctype.h>int main( void ){ int i=0; char ch; puts("Input an integer followed by a char:"); /* read chars until non digit or EOF */ while((ch = getchar()) != EOF && isdigit(ch)) i = 10 * i + ch - 48; /* convert ASCII into int value */ /* if non digit char was read, push it back into input buffer */ if (ch != EOF) ungetc(ch, stdin); printf("i = %d, next char in buffer = %c\n", i, getchar()); return 0;}#include <stdio.h>#include <ctype.h>#include <conio.h>int main( void ){ int i=0; char ch; puts("Input an integer followed by a char:"); /* read chars until non digit or EOF */ while((ch = getche()) != EOF && isdigit(ch)) i = 10 * i + ch - 48; /* convert ASCII into int value */ /* if non digit char was read, push it back into input buffer */ if (ch != EOF) ungetch(ch); printf("\n\ni = %d, next char in buffer = %c\n", i, getch()); return 0;}#include <stdio.h>#include <dos.h>char *month[] = {"---", "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};#define SECONDS_PER_DAY 86400L /* the number of seconds in one day */struct date dt;struct time tm;int main(void){ unsigned long val;/* get today's date and time */ getdate(&dt); gettime(&tm); printf("today is %d %s %d\n", dt.da_day, month[dt.da_mon], dt.da_year);/* convert date and time to unix format (number of seconds since Jan 1, 1970 */ val = dostounix(&dt, &tm);/* subtract 42 days worth of seconds */ val -= (SECONDS_PER_DAY * 42);/* convert back to dos time and date */ unixtodos(val, &dt, &tm); printf("42 days ago it was %d %s %d\n", dt.da_day, month[dt.da_mon], dt.da_year); return 0;}#include <stdio.h>#include <io.h>int main(void){ FILE *fp = fopen("junk.jnk","w"); int status; fprintf(fp,"junk"); status = access("junk.jnk",0); if (status == 0) printf("File exists\n"); else printf("File doesn't exist\n"); fclose(fp); unlink("junk.jnk"); status = access("junk.jnk",0); if (status == 0) printf("File exists\n"); else printf("File doesn't exist\n"); return 0;}#include <io.h>#include <fcntl.h>#include <sys\stat.h>#include <process.h>#include <share.h>#include <stdio.h>int main(void){ int handle, status; long length; handle = sopen("c:\\autoexec.bat",O_RDONLY,SH_DENYNO,S_IREAD); if (handle < 0) { printf("sopen failed\n"); exit(1); } length = filelength(handle); status = lock(handle,0L,length/2); if (status == 0) printf("lock succeeded\n"); else printf("lock failed\n"); status = unlock(handle,0L,length/2); if (status == 0) printf("unlock succeeded\n"); else printf("unlock failed\n"); close(handle); return 0;}
