2023 work

Wip/dj/dj.c

@@ -8,6 +8,16 @@
 
 #define ARGV0 (argv[0] == NULL ? "<no argv[0]>" : argv[0])
 
+/* read(2) but with a second chance if it returns zero */
+static int
+_read(int fd, void *b, size_t bs){
+	int retval;
+
+	return ((retval = read(fd, buf, bs)) == 0)
+		? read(fd, buf, bs)
+		: retval;
+}
+
 static int /* on error returns -1, else returns non-negative */
 parse(char *s){
 	int r;
@@ -27,6 +37,28 @@ oserr(char *argv0, char *s){
 	return EX_OSERR;
 }
 
+struct Io *
+output(struct Io io[2]){
+
+	fprintf(stderr, "%d:%d / %d:%d\n",
+		io[0].rec, io[0].prec, io[1].rec, io[1].prec);;
+	return io;
+}
+
+static int
+terminate(struct Io io[2]){
+
+	for(;; ++io){
+		if(io->fd != STDIN_FILENO && io->fd != STDOUT_FILENO)
+			close(io->fd);
+		free(io->buf);
+		if(io->index == 1)
+			break;
+	}
+
+	return EX_OK;
+}
+
 static int
 usage(char *argv0){
 	fprintf(stderr, "Usage: %s (-f) (-c [count]\n"
@@ -42,6 +74,7 @@ static char stdout_name = "<stdout>";
 
 int main(int argc, char *argv[]){
 	struct Io{
+		size_t index;
 		char align;
 		char *fn;
 		int rec;
@@ -67,6 +100,8 @@ int main(int argc, char *argv[]){
 	io[0].fn = stdin_name;
 	io[1].fd = STDOUT_FILENO;
 	io[1].fn = stdout_name;
+	io[0].index = 0;
+	io[1].index = 1;
 	io[0].seek = io[1].seek = 0;
 
 	if(argc > 0)
@@ -113,13 +148,11 @@ int main(int argc, char *argv[]){
 		}else if(io[p].seek > 0){ /* seek */
 			if(io[p].fd == STDIN_FILENO){
 				do{	io[p].seek -= (io[p].bufuse
-						= read(io[p].fd, io[p].buf, io[p].ibs));
+						= _read(io[p].fd, io[p].buf,
+							io[p].bs < io[p].seek ? io[p].bs : io[p].seek));
 					if(io[p].bufuse == 0)
-				while(io[p].seek > 0);
-
-			}
-				for(i = 0; i < io[p].seek; ++i)
-					(void)getc(io[p].f);
+						return terminate(output(io));
+				}while(io[p].seek > 0);
 			else if(io[p].f == stdout)
 				for(i = 0; i < io[p].seek; ++i)
 					putc('\0', io[p].f;