K & R C Programs Exercise 7-7.

K and R C, Solution to Exercise 7-7:
K and R C Programs Exercises provides the solution to all the exercises in the C Programming Language (2nd Edition). You can learn and solve K&R C Programs Exercise.
C program to modify the pattern-finding program of chapter 5(C Programming Language  2nd Edition, page no 117.) to take its input from a set of named files or, if no files are named as arguments, from the standard input. Should the file name be printed when a matching line is found.Read more about C Programming Language .
/***********************************************************
* You can use all the programs on www.c-program-example.com
* for personal and learning purposes. For permissions to use the
* programs for commercial purposes,
* contact info@c-program-example.com
* To find more C programs, do visit www.c-program-example.com
* and browse!
*
* Happy Coding
***********************************************************/

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

#define MAXLINE 1000

/*print lines that match pattern from 1st argument */
main(int argc, char *argv[])
{
char pattern[MAXLINE];
int c, excpet = 0,number = 0;
FILE *fp;
void fpat(FILE *fp, char *fname, char *pattern, int except, int number);

while(--argc > 0 && (*++argv)[0] == '-')
while(c = *++argv[0])
switch(c) {
case 'x':
except = 1;
break;
case 'n':
number = 1;
break;
default:
printf("find:illigal option %cn",c);
argc = 0;
break;
}
if(argc >= 1)
strcpy(pattern, *argv);
else{
printf("Usage:find[-x] [-n] pattern [file....]n");
exit(1);
}
if(argc == 1)
fpat(stdin,"",pattern,except,number);
else
while(--argc > 0)
if((fp = fopen(*++argv,"r")) == NULL) {
fprintf(stderr,"find:can't open %sn",*argv);
exit(1);
} else {
fpat(fp, *argv, pattern,except,number);
fclose(fp);}
return 0;
}

/*fpat: find pattern*/
void fpat(FILE *fp, char *fname, char *pattern, int except, int number)
{
char line[MAXLINE];
long loneno = 0;

while(fgets(line, MAXLINE, fp) != NULL){
++lineno;
if((strstr(line,pattern) != NULL) !=except) {
if(*fname)
printf("%s -",fname);
if(number)
printf("%ld: ",lineno);
printf("%s",line);
}
}
}



Read more c programs

C Basic
C Strings
K and R C Programs Exercise

You can easily select the code by double clicking on the code area above.

To get regular updates on new C programs, you can Follow @c_program

You can discuss these programs on our Facebook Page. Start a discussion right now,

our page!

Share this program with your Facebook friends now! by liking it

(you can send this program to your friend using this button)

Like to get updates right inside your feed reader? Grab our feed!

To browse more C Programs visit this link
(c) www.c-program-example.com

K & R C Programs Exercise 7-6.

K and R C, Solution to Exercise 7-6:
K and R C Programs Exercises provides the solution to all the exercises in the C Programming Language (2nd Edition). You can learn and solve K&R C Programs Exercise.
Write a C Program to compare two files, printing the first line where they differ.
Read more about C Programming Language .
/***********************************************************
* You can use all the programs on www.c-program-example.com
* for personal and learning purposes. For permissions to use the
* programs for commercial purposes,
* contact info@c-program-example.com
* To find more C programs, do visit www.c-program-example.com
* and browse!
*
* Happy Coding
***********************************************************/

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

#define MAXLINE 100
/*comp: compare two file, printing the first line where they differ*/
main(int argc, char *argv[])
{
FILE *fp1, *fp2;
void filecomp(FILE *fp1, FILE *fp2);
if(argc != 3){
fprintf(stderr,"comp:need two file namesn");
exit(1);
} else {
if((fp1 = fopen(*++argv, "r")) == NULL) {
fprintf(stderr, "comp:can't open %sn",*argv);
exit(1);
} else if((fp2 = fopen(*++argv, "r")) == NULL) {
fprintf(stderr, "comp:can't open %sn",*argv);
exit(1);
}else {
filecomp(fp1,fp2);
fclose(fp1);
fclose(fp2);
exit(0);

}
}
}

//filecomp: compare two files -a line at a time
void filecomp (FILE *fp1, FILE *fp2)
{
char line1[MAXLINE], line2[MAXLINE];
char *lp1 = *lp2;
do{
lp1 = fgets(line1, MAXLINE, fp1);
lp2 = fgets(line2, MAXLINE, fp2);
if(lp1 == line1 && lp2 == line2){

if(strcmp(line1,line2) !=0) {
printf("First difference in linen%sn",line1);
lp1 = lp2 = NULL;
}
} else if(lp1 != line1 && lp2 == line2)
printf("end of first file at linen%sn",line2);
else if(lp1 == line1 && lp2 == line2)
printf("end of second file at line n%sn",line1);

}while(lp1 == line1 && lp2 == line2);
}



Read more c programs

C Basic
C File i/o
K and R C Programs Exercise

You can easily select the code by double clicking on the code area above.

To get regular updates on new C programs, you can Follow @c_program

You can discuss these programs on our Facebook Page. Start a discussion right now,

our page!

Share this program with your Facebook friends now! by liking it

(you can send this program to your friend using this button)

Like to get updates right inside your feed reader? Grab our feed!

To browse more C Programs visit this link
(c) www.c-program-example.com

K & R C Programs Exercise 7-5.

K and R C, Solution to Exercise 7-5:
K and R C Programs Exercises provides the solution to all the exercises in the C Programming Language (2nd Edition). You can learn and solve K&R C Programs Exercise.
Rewrite the postfix calculator of chapter 4 to use scanf and/or sscanf to do the input number conversion.
Read more about C Programming Language .
/***********************************************************
* You can use all the programs on www.c-program-example.com
* for personal and learning purposes. For permissions to use the
* programs for commercial purposes,
* contact info@c-program-example.com
* To find more C programs, do visit www.c-program-example.com
* and browse!
*
* Happy Coding
***********************************************************/



#include<stdio.h>
#include<math.h> /*for atof()*/
#define MAXTOP 100 /* max size of operand or operator */
#define NUMBER '0' /* SIGNAL THAT A NUMBER WAS FOUND */
#define MAXVAL 100
int gettop(char []);
void push(double);
double pop(void);
int sp = 0; /* Next free stack position. */
double val[MAXVAL];


//reverse Polish calulator
int main(void)
{
int type;
double op2;
char s[MAXOP];

while((type = getop(s)) != EOF)
{
switch(type)
{
case NUMBER:
push(atof(s));
break;
case '+':
push(pop() + pop());
break;
case '*':
push(pop() * pop());
break;

case '-':
op2=pop();
push(pop() - op2);
break;
case '-':
op2=pop();
if(op2 != 0.0)
push(pop() / op2);
else printf("nError: Zero divissorn");
break;
case '%':
op2 = pop();
if(op2)
push(fmod(pop(), op2));
else
printf("nError: Division by zero!");
break;
case 'n':
printf("t%.8gn",pop());
break;
default:
printf("error: unknown command %sn", s);
break;

}
}
return 0;
}




/* Getop: get next operator or numeric operand. */
int getop(char s[])
{

int i = 0;
int c;
int rc;
static char lastc[] = " ";
sscanf(lastc,"%c", &c);
lastc[0] = ' ';

/* Skip whitespace */
while((s[0] = c ) == ' ' || c == 't')
if(scanf("%",&c) == EOF)
c = EOF;
s[1] = '