simplify

echo/Makefile

@@ -2,19 +2,10 @@ TARGETS = echo prompt
 
 all: $(TARGETS)
 
-echo: echo.c
+%: %.c
 	$(CC) -o $@ $@.c
 
-prompt: echo.c
-	$(CC) -DPROMPT -o $@ echo.c
-
 clean:
 	rm -f $(TARGETS)
 
-sane: echo.c ../sysexits/sysexits.h
-	$(CC) -DDONT_USE_SYSTEM_SYSEXITS -o echo echo.c
-
-../sysexits/sysexits.h:
-	$(MAKE) -C ../sysexits sysexits.h
-
-.PHONY: all clean sane
+.PHONY: all clean

echo/echo.c

@@ -1,25 +1,16 @@
+#include <stdio.h> /* NULL, fprintf(3), putc(3) */
+#include <stdlib.h> /* stdout */
 #include <sysexits.h> /* EX_OK */
-#include <stddef.h> /* NULL */
-#include <unistd.h> /* write(2) */
 
 int main(int argc, char **argv){
-	int i;
 
-	if(*argv == NULL)
-		goto blank;
-	
-	++argv;
-
-	while(--argc){
-		for(i = 0; argv[0][i] != '\0'; ++i);
-		write(1, *(argv++), i);
-		if(argc > 1)
-			write(1, " ", 1);
+	if(*argv == NULL || *++argv == NULL){
+		argc = 1;
+		putc('\n', stdout);
 	}
 
-blank:
-#ifndef PROMPT
-	write(1, "\n", 1);
-#endif
+	while(--argc)
+		fprintf(stdout, "%s%c", *(argv++), argc > 1 ? ' ' : '\n');
+
 	return EX_OK;
 }

echo/prompt.c

@@ -0,0 +1,17 @@
+#include <stdio.h> /* NULL, fprintf(3), putc(3) */
+#include <stdlib.h> /* stdout */
+#include <sysexits.h> /* EX_OK */
+
+int main(int argc, char **argv){
+
+	if(*argv == NULL || *++argv == NULL)
+		argc = 1;
+
+	while(--argc){
+		fprintf(stdout, "%s", *(argv++));
+		if(argc > 1)
+			putc(' ', stdout);
+	}
+
+	return EX_OK;
+}