C Prime Plus第十三章

1.

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

int main(void)
{
char name[41];
int ch;
FILE *fp;
long count = 0;

printf("Input the file's name: ");
scanf("%s", &name);
if((fp = fopen(name, "r")) == NULL)
{
printf("Can't open %s\n", name);
exit(1);
}
while((ch = getc(fp)) != EOF)
{
putc(ch, stdout);
count++;
}
fclose(fp);
printf("File %s has %ld characters\n", name, count);
return 0;
}

2.

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

int main(int argc, char * argv[])
{
int ch;
FILE *source, *desitination;

if((source = fopen(argv[1], "rb")) == NULL)
{
fprintf(stderr, "Can't open.\n");
exit(1);
}
if((desitination = fopen(argv[2], "rb")) == NULL)
{
fprintf(stderr, "Can't open.\n");
exit(2);
}
while((ch = getc(source)) != EOF)
putc(ch, desitination);
fclose(source);
fclose(desitination);
fprintf(stdout, "copy finished.\n");
return 0;
}

3.

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

int main(int argc, char *argv[])
{
int ch;
FILE *source, *desitination;
char s_name[41], d_name[41];

printf("Input the source name:");
if(source = fopen(gets(s_name), "r"))
{
printf("Can't open.\n");
exit(1);
}
printf("Input the desitination:");
if(source = fopen(gets(d_name), "r"))
{
printf("Can't open.\n");
exit(1);
}
while((ch = getc(source)) != 0)
putc(toupper(ch), desitination);
fclose(source);
fclose(desitination);
pritnf("copy finished.\n");
return 0;
}

5.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define BUFSIZE 1024
#define SLEN 81
void append(FILE * source, FILE *dest);

int main(int argc, int argv[])
{
FILE *fa, *fs;
int files = 0, i;
char file_app[SLEN] ;
char file_src[SLEN];

if((fa = fopen(argv[1],"a")) ==  NULL)
{
fprintf(stderr, "Can't open %s\n", file_app);
exit(2);
}
if(setvbuf(fa, NULL, _IOFBF, BUFSIZE) != 0)
{
fputs("Can't create output buffer\n", stderr);
exit(3);
}
for(i = 2; i<argc; i++)
{
if(strcmp(argv[i], argv[1]) == 0)
fputs("Can't append file to itself\n", stderr);
else if((fs = fopen(argv[i], "r")) == NULL)
fprintf(stderr, "Can't open %s\n", argv[1]);
else
{
if(setvbuf(fs, NULL, _IOFBF, BUFSIZE) != 0)
{
fputs("Can't create input buffer.\n", stderr);
continue;
}
append(fs, fa);
if(ferror(fs) != 0)
fprintf(stderr, "Error in reading file %s.\n",
argv[1]);
if(ferror(fa) != 0)
fprintf(stderr, "Error in writing file %s.\n",
argv[i]);
fclose(fs);
files++;
printf("File %s append.\n", argv[1]);
puts("Next file(empty line to quit):");
}
}
printf("Done. %d files append.\n", files);
fclose(fa);
return 0;
}

void append(FILE *source, FILE *dest)
{
size_t bytes;
static char temp[BUFSIZE];

while((bytes = fread(temp, sizeof(char), BUFSIZE, source)) > 0)
fwrite(temp, sizeof(char), bytes, dest);
}

6.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define LEN 40
int main(void)
{
FILE *in, *out;
int ch;
char name[LEN];
int count = 0;

puts("Enter the file's name to reduce:");
gets(name);
if((in = fopen(name,"r")) == NULL)
{
fprintf(stderr, "I couldn't open the file \%s\n", name);
exit(2);
}
name[LEN - 5] = '\0';
strcat(name, ".red");
if((out = fopen(name, "w")) == NULL)
{
fprintf(stderr, "Can't create output file.\n");
exit(3);
}
while((ch = getc(in)) != EOF)
if(count++ %3 == 0)
putc(ch, out);
if(fclose(in) != 0 || fclose(out) != 0)
fprintf(stderr, "Error in closing files\n");
return 0;
}

7.

8.

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

int count(char ch, FILE *fp);

int main(int argc, int argv[])
{
FILE *fp;
char ch;
int i;

if(argv < 2)
{
printf("No char?\n");
exit(1);
}
ch = argv[1][0];
if(argv == 2)
{
printf("Input your article:");
printf("In your input: %c appeared %d times.\n", ch, count(ch, stdin));
}
else
for(i=2; i<argc; i++)
{
if((fp = fopen(argv[i], "r")) == NULL)
printf("Can't open %s.\n", argv[i]);
else
{
printf("In %s:%c has appeared %d times.\n", argv[i], ch, count(ch, fp));
fclose(fp);
}
}
return 0;
}

int count(char ch, FILE *fp)
{
int n=0;
char ch2;
while((ch2 = getc(fp)) != EOF)
if(ch == ch2)
n++;
return 0;
}

9.

#include <stdio.h>
#include <stdlib.h>
#define MAX 40

int main(void)
{
FILE *fp;
char words[MAX];
int count = 0;

if((fp = fopen("word", "a+")) == NULL)
{
fprintf(stdout, "Can't open \"words\" file.\n");
exit(1);
}
rewind(fp);
while(fgets(words, MAX-1, fp) != NULL)
count++;
puts("Enter words to add to the file;press the Enter");
puts("key at the beginning of a line to terminate.");
while(gets(words) != NULL && words[0] != '\0')
fprintf(fp, "%s", words);
puts("File contents:");
rewind(fp);
while(fscanf(fp, "%s", words) == 1)
puts(words);
if(fclose(fp) != 0)
fprintf(stderr, "Error closing file\n");
return 0;
}

10.

#include <stdio.h>
#include <stdlib.h>
#define MAX 81

int main(void)
{
char name[30],content[MAX];
int row, column;
FILE *fp;
printf("input the name of file:");
gets(name);
if((fp =fopen(name, "r")) == NULL)
{
printf("Can't open %s", name);
exit(1);
}
printf("input the row and columnto output:");
while(scanf("%d%d", &row, &column) == 2)
{
row--, column--;
fseek(fp, 0, SEEK_SET);
while(row--)
fgets(content, MAX, fp);
printf(content);
printf("input the start position to output:");
}
printf("Quit.\n");
return 0;
}

11.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 201

int main(int argc, int argv[])
{
FILE *fp;
char str[MAX];
if((fp = fopen(argv[2], "r")) == NULL)
{
printf("Can't open %s.\n", fp);
exit(1);
}
while(fgets(str, MAX, fp) != NULL)
if(strstr(str, argv[1]) != NULL)
printf(str);
return 0;
}