more cleanup

mm/mm.c

@@ -91,44 +91,28 @@ oserr(char *s, char *r){
 	return EX_OSERR;
 }
 
-/* Destructs the files[2] struct used by main by closing its files and freeing
+/* Hijacks i and j from main and destructs the files[2] struct used by main by
- * its files and names arrays. Returns the destructed files. */
+/* closing its files and freeing its files and names arrays, returning retval
-static struct Files *
+ * from main. */
-terminate(struct Files *files){
+#define terminate \
-	size_t i;
+	for(i = 0; i < 2; ++i){ \
-	size_t j;
+		for(j = 0; j < files[i].s; ++j) \
-
+			if(files[i].files[j] != stdin \
-	for(i = 0; i < 2; ++i){
+					&& files[i].files[j] != stdout \
-		for(j = 0; j < files[i].s; ++j)
+					&& files[i].files[j] != stderr) \
-				if(files[i].files[j] != stdin
+				fclose(files[i].files[j]); \
-						&& files[i].files[j] != stdout
+		free(files[i].files); \
-						&& files[i].files[j] != stderr)
+		free(files[i].names); \
-					fclose(files[i].files[j]);
+	} \
-			free(files[i].files);
+	return retval
-			free(files[i].names);
-	}
-
-	return files;
-}
 
 int main(int argc, char *argv[]){
 	int c;
+	struct Files files[2]; /* {read, write} */
 	size_t i;
 	size_t j;
-	size_t k;
+	size_t k; /* loop index but also unbuffer status */
-	struct Files files[2]; /* {read, write} */
+	int retval;
-	int s; /* scratch variable */
-
-	/* The simple invocation (without given arguments) requires no memory
-	 * allocations or use of the files structs and is therefore treated as
-	 * a special case. To do the same with all bells and whistles call
-	 * $ mm -i - -o - */
-	if(argc < 2){ /* simple invocation */
-		while((c = getc(stdin)) != EOF)
-			if(putc(c, stdout) == EOF)
-				return 1;
-		return 0;
-	}
 
 	/* Initializes the files structs with their default values, standard
 	 * input and standard output. If an input or an output is specified
@@ -146,7 +130,7 @@ int main(int argc, char *argv[]){
 		files[i].s = 0;
 	}
 
-	s = 0; /* Refers to whether or not files will be unbuffered. */
+	k = 0;
 
 	while((c = getopt(argc, argv, "aehi:no:u")) != -1)
 		switch(c){
@@ -158,16 +142,16 @@ int main(int argc, char *argv[]){
 			if(Files_append(&files[1], stderr, stderr_name)
 					!= NULL)
 				break;
-			terminate(files);
+			retval = oserr(argv[0], "-e");
-			return oserr(argv[0], "-e");
+			terminate;
 		case 'i':
 			if((strcmp(optarg, "-") == 0 && Files_append(&files[0],
 						stdin, stdin_name) != NULL)
 					|| Files_open(&files[0], optarg)
 						!= NULL)
 				break;
-			terminate(files);
+			retval = oserr(argv[0], optarg);
-			return oserr(argv[0], optarg);
+			terminate;
 		case 'o':
 			if((strcmp(optarg, "-") == 0 && Files_append(&files[1],
 						stdout, stdout_name) != NULL)
@@ -182,29 +166,29 @@ int main(int argc, char *argv[]){
 					break;
 				}
 			}
-			terminate(files);
+			retval = oserr(argv[0], optarg);
-			return oserr(argv[0], optarg);;
+			terminate;
 		case 'n':
 			if(signal(SIGINT, SIG_IGN) != SIG_ERR)
 				break;
-			terminate(files);
+			retval = oserr(argv[0], "-n");
-			return oserr(argv[0], "-n");
+			terminate;
 		case 'u':
-			s = 1;
+			k = 1;
 			break;
 		default:
 			fprintf(stderr, "Usage: %s (-aehnu)"
 				" (-i [input])... (-o [output])...\n",
 				argv[0]);
-			terminate(files);
+			retval = EX_USAGE;
-			return EX_USAGE;
+			terminate;
 		}
 
 	files[0].s += files[0].s == 0;
 	files[1].s += files[1].s == 0;
 	
 	/* Unbuffer files. */
-	if(s){	for(	i = 0;
+	if(k){	for(	i = 0;
 			i < files[0].s;
 			setvbuf(files[0].files[i++], NULL, _IONBF, 0));
 		for(	i = 0;
@@ -212,10 +196,7 @@ int main(int argc, char *argv[]){
 			setvbuf(files[1].files[i++], NULL, _IONBF, 0));
 	}
 
-	/* Reflects whether (s==0) or not (s==1) the full length of the inputs
+	retval = 0;
-	 * could be written to all outputs, which is the return value for main
-	 * to maintain feature parity with tee(1p). */
-	s = 0;
 
 	/* Actual program loop. */
 	for(i = 0; i < files[0].s; ++i) /* iterate ins */
@@ -223,7 +204,7 @@ int main(int argc, char *argv[]){
 			for(j = 0; j < files[1].s; ++j) /* iterate outs */
 				if(putc(c, files[1].files[j]) == EOF){
 					/* notebook's full */
-					s = 1;
+					retval = 1;
 					if(fclose(files[1].files[j]) == EOF)
 						fprintf(stderr, "%s: %s: %s\n",
 							program_name,
@@ -236,13 +217,9 @@ int main(int argc, char *argv[]){
 						files[1].names[k]
 							= files[1].names[k+1];
 					}
-					if(--files[i].s == 0){
+					if(--files[i].s == 0)
-						terminate(files);
+						terminate;
-						return 1;
-					}
 				}
 
-	terminate(files);
+	terminate;
-
-	return s;
 }