Exercise 1-19. Write a function reverse(s)

02-vars-and-math.c

@@ -4,6 +4,8 @@
 #define  UPPER  300
 #define  STEP   20
 
+float convert(int f);
+
 /* print Fahrenheit-Celsius table */
 int main()
 {
@@ -11,5 +13,10 @@ int main()
 
 	printf("Fahrenheit\tCelsius\n=======================\n");
 	for (fahr = UPPER; fahr >= LOWER; fahr = fahr - STEP)
-		printf("%3d\t\t%7.1f\n", fahr, (5.0/9.0)*(fahr-32));
+		printf("%3d\t\t%7.1f\n", fahr, convert(fahr));
+}
+
+float convert(int fahr)
+{
+	return (5.0/9.0)*(fahr-32);
 }

07-extra-blanks.c

@@ -0,0 +1,16 @@
+#include <stdio.h>
+
+int main()
+{
+	int c;
+	int l;
+
+	while ((c = getchar()) != EOF) {
+		if (c == ' ' && c == l) {
+			;
+		} else {
+			printf("%c", c);
+			l = c;
+		}
+	}
+}

08-unambiguous.c

@@ -0,0 +1,17 @@
+#include <stdio.h>
+
+int main()
+{
+	int c;
+
+	while ((c = getchar()) != EOF) {
+		if (c == '\t')
+			printf("\\t");
+		else if (c == '\b')
+			printf("\\b");
+		else if (c == '\\')
+			printf("\\\\");
+		else
+			printf("%c", c);
+	}
+}

09-word-count.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+
+#define IN  1
+#define OUT 0
+
+/* count lines, words, and characters in input */
+int main()
+{
+	int c, nl, nw, nc, state;
+
+	state = OUT;
+	nl = nw = nc = 0;
+	while ((c = getchar()) != EOF) {
+		++nc;
+		if (c == '\n')
+			++nl;
+		if (c == ' ' || c == '\n' || c == '\t')
+			state = OUT;
+		else if (state == OUT) {
+			state = IN;
+			++nw;
+		}
+	}
+	printf("%d %d %d\n", nl, nw, nc);
+}

10-one-word-per-line.c

@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+int main()
+{
+	int c;
+
+	while((c = getchar()) != EOF) {
+		if (c == ' ' || c == '\n' || c == '\t')
+			printf("\n");
+		else
+			printf("%c", c);
+	}
+
+}

11-arrays.c

@@ -0,0 +1,26 @@
+#include <stdio.h>
+
+/* count digits, white space, others */
+int main()
+{
+	int c, i, nwhite, nother;
+	int ndigit[10];
+
+	nwhite = nother = 0;
+	for(i = 0; i < 10; ++i)
+		ndigit[i] = 0;
+
+	while ((c = getchar()) != EOF)
+		if (c >= '0' && c <= '9')
+			++ndigit[c-'0'];
+		else if (c == ' ' || c == '\n' || c == '\t')
+			++nwhite;
+		else
+			++nother;
+
+	printf("digits =");
+	for (i = 0; i < 10; ++i)
+		printf(" %d", ndigit[i]);
+	printf(", white space = %d, other = %d\n",
+		nwhite, nother);
+}

12-histogram.c

@@ -0,0 +1,55 @@
+#include <stdio.h>
+
+#define IN       1
+#define OUT      0
+#define MAXERROR "WARNING: Word length '%d' exceeded 99\n"
+
+int main()
+{
+	int c, i, j, state, count, top;
+	int wordl[100];
+
+	count = state = top = OUT;
+	for(i = 0; i < 100; ++i)
+		wordl[i] = 0;
+
+	while ((c = getchar()) != EOF) {
+		if (c == ' ' || c == '\n' || c == '\t') {
+			state = OUT;
+			if (count > 0 && count < 100)
+				++wordl[count];
+			else if (count >= 100)
+				printf(MAXERROR, count);
+			count = 0;
+		} else {
+			++count;
+			if (state == OUT)
+				state = IN;
+		}
+	}
+
+	if (count > 0 && count < 100)
+		++wordl[count];
+	else if (count >= 100)
+		printf(MAXERROR, count);
+
+	for (i = 0; i < 100; ++i)
+		if (wordl[i] > top)
+			top = wordl[i];
+
+	printf("\n");
+	for (i = 0; i < 100; ++i)
+		if (wordl[i] > 0)
+			printf("%2d ", i);
+
+	printf("\n");
+	for (i = 1; i <= top; ++i) {
+		for (j = 0; j < 100; ++j) {
+			if (wordl[j] >= i)
+				printf(" # ");
+			else if (wordl[j] > 0)
+				printf("   ");
+		}
+		printf("\n");
+	}
+}

13-functions.c

@@ -0,0 +1,24 @@
+#include <stdio.h>
+
+int power(int m, int n);
+
+/* test power function */
+int main()
+{
+	int i;
+
+	for (i = 0; i < 10; ++i)
+		printf("%d %d %d\n", i, power(2,i), power(-3,i));
+	return 0;
+}
+
+/* power: raise base to n-th power; n >= 0 */
+int power(int base, int n)
+{
+	int i, p;
+
+	p = 1;
+	for (i = 1; i <= n; ++i)
+		p = p * base;
+	return p;
+}

14-char-arrays.c

@@ -0,0 +1,81 @@
+#include <stdio.h>
+#define MAXLINE 1000 /* maximum input line size */
+#define MINLINE 0
+
+int getline(char line[], int maxline);
+void copy(char to[], char from[]);
+void trim(char line[], int len);
+void reverse(char to[], char from[], int len);
+
+/* print longest input line */
+main()
+{
+	int len;
+	int max;
+	int c;
+	char line[MAXLINE];
+	char enil[MAXLINE];
+
+	max = 0;
+	while((len = getline(line, MAXLINE)) > 0) {
+		if (line[len-1] != '\n') {
+			while ((c=getchar())!=EOF && c!='\n')
+				++len;
+			if (c == '\n')
+				++len;
+		}
+		if (len >= MINLINE) {
+			reverse(enil, line, len);
+			printf("%s", enil);
+		}
+	}
+	return 0;
+}
+
+/* getline: read a line into s, return length */
+int getline(char s[], int lim)
+{
+	int c, i;
+
+	for (i=0; i<lim-1 && (c=getchar())!=EOF && c!='\n'; ++i)
+		s[i] = c;
+	if (c == '\n') {
+		s[i] = c;
+		++i;
+	}
+	s[i] = '\0';
+	return i;
+}
+
+/* copy: copy 'from' into 'to': assume to is big enough */
+void copy(char to[], char from[])
+{
+	int i;
+
+	i = 0;
+	while ((to[i] = from[i]) != '\0')
+		++i;
+}
+
+/* trim: remove extraneous blanks and tabs */
+void trim(char s[], int len)
+{
+	int i;
+
+	for (i = len-2; i >= 0; --i)
+		if (s[i] == ' ' || s[i] == '\t')
+			s[i] = '\0';
+		else
+			return;
+}
+
+void reverse(char to[], char from[], int len)
+{
+	int i;
+
+	i = 0;
+	while ((to[i] = from[len-1]) != '\0') {
+		++i;
+		--len;
+	}
+}

Makefile

@@ -1,22 +1,10 @@
-all: hello mathvars c2f input count countlines
+CC   = gcc
+OBJS = $(patsubst %.c,bin/%,$(wildcard *.c))
 
-hello: 01-hello-world.c
-	gcc -o ./bin/01-helloworld 01-hello-world.c
+all: $(OBJS)
 
-mathvars: 02-vars-and-math.c
-	gcc -o ./bin/02-mathvars 02-vars-and-math.c
-
-c2f: 03-celsius-to-fahrenheit.c
-	gcc -o ./bin/03-c2f 03-celsius-to-fahrenheit.c
-
-input: 04-file-copying.c
-	gcc -o ./bin/04-input 04-file-copying.c
-
-count: 05-char-counting.c
-	gcc -o ./bin/05-count 05-char-counting.c
-
-countlines: 06-line-count.c
-	gcc -o ./bin/06-line-count 06-line-count.c
+$(OBJS):
+	$(CC) -o ./$@ $(patsubst bin/%,%.c,$@) -ansi
 
 clean:
-	$(RM) ./bin/*-*
+	$(RM) ./bin/*

README.adoc

@@ -152,3 +152,68 @@ https://github.com/krislamo/knrc/commit/588969b09fabab1e91ff4f4b1c37e87fc23cf76b
 https://github.com/krislamo/knrc/blob/588969b09fabab1e91ff4f4b1c37e87fc23cf76b/02-vars-and-math.c[(Source)]
 
 Move some numbers around to reverse the table.
+
+09-word-count.c
+~~~~~~~~~~~~~~~~
+https://github.com/krislamo/knrc/commit/d064db2b171e3da74fd5082ae29456f64caeafeb[(Diff)]
+https://github.com/krislamo/knrc/blob/d064db2b171e3da74fd5082ae29456f64caeafeb/09-word-count.c[(Source)]
+
+Textbook example of counting lines, words, and characters from input.
+
+Exercise 1-11: test the word count program
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+No input:
+
+----
+$ ./bin/09-word-count
+0 0 0
+$
+----
+
+Just 3 newlines:
+
+----
+$ ./bin/09-word-count
+
+
+
+3 0 3
+$
+----
+
+Just 3 tabs:
+
+----
+$ ./bin/09-word-count
+                        0 0 3
+$
+----
+
+Just 3 spaces:
+
+----
+$ ./bin/09-word-count
+   0 0 3
+$
+----
+
+Just a single word per line:
+
+----
+$ ./bin/09-word-count
+one
+word
+per
+line
+4 4 18
+$
+----
+
+Three blanks before and after:
+
+----
+$ ./bin/09-word-count
+   three blanks before/after   0 3 31
+$
+----