mm(1)

Wip/mm/Makefile

@@ -0,0 +1 @@
+mm: mm.c

Wip/mm/mm.c

@@ -0,0 +1,326 @@
+#include <errno.h> /* errno */
+#include <stdio.h> /* fclose(3), fopen(3), fprintf(3), getc(3), putc(3),
+                    * setvbuf(3), size_t, _IONBF, NULL */
+#include <stdlib.h> /* free(3), realloc(3) */
+#include <string.h> /* strerror(3) */
+#include <unistd.h> /* getopt(3) */
+#if !defined EX_OK || !defined EX_USAGE
+#	include <sysexits.h>
+#endif
+
+struct Io_ex{
+	size_t s;
+	FILE **files;
+	char **names;
+};
+
+struct Io{
+	size_t s;
+	FILE *files[10];
+	char *names[10];
+	char *fmode;
+	struct Io_ex *ex;
+};
+
+static char *program_name = "<no argv[0]>";
+static char *stdin_name = "<stdin>";
+static char *stdout_name = "<stdout>";
+static char *stderr_name = "<stderr>";
+static char *rmode = "rb";
+static char *wmode = "rb+";
+static char *wharsh = "wb";
+
+#define terminate(io) do{ \
+	Io_destruct(&(io)[0]); \
+	Io_destruct(&(io)[1]); }while(0)
+
+static struct Io *
+Io_construct(struct Io *io){
+
+	io->s = 0;
+	io->ex->s = 0;
+	io->ex->files = NULL;
+	io->ex->names = NULL;
+
+	return io;
+}
+
+static struct Io *
+Io_destruct(struct Io *io){
+	size_t i;
+
+	for(i = 0; i < io->s; ++i)
+		fclose(io->files[i]);
+
+	for(i = 0; i < io->ex->s; ++i)
+		fclose(io->ex->files[i]);
+	free(io->ex->files);
+	free(io->ex->names);
+
+	return Io_construct(io); /* counter-intuitive but NULLs and 0s */
+}
+
+static FILE *
+Io_fappend(struct Io *io, FILE *f, char *s){
+
+	if(io->s == -1)
+		io->s = 0;
+
+	if(io->s < (sizeof (io->files)) / (sizeof *(io->files))){
+		io->names[io->s] = s;
+		return io->files[io->s++] = f;
+	}else{
+		io->ex->files = realloc(io->ex->files,
+			(sizeof *(io->ex->files)) * ++io->ex->s);
+		io->ex->names = realloc(io->ex->names,
+			(sizeof *(io->ex->names)) * io->ex->s);
+		io->ex->names[io->ex->s] = s;
+		return io->ex->files[io->ex->s++] = f;
+	}
+}
+
+static int
+Io_fileindex(struct Io *io, FILE *f){
+	size_t i;
+
+	for(i = 0; i < io->s; ++i)
+		if(io->files[i] == f)
+			return i;
+
+	for(i = 0; i < io->ex->s; ++i)
+		if(io->ex->files[i] == f)
+			return i + io->s;
+
+	return -1;
+}
+
+static char *
+Io_filename(struct Io *io, FILE *f){
+	int i;
+
+	if((i = Io_fileindex(io, f)) == -1)
+		return NULL;
+	else if(i < io->s - 1)
+		return io->names[i];
+	else
+		return io->ex->names[i - io->s];
+}
+
+static FILE *
+Io_fopen(struct Io *io, char *s){
+	FILE *f;
+
+	if((f = fopen(s, io->fmode)) == NULL)
+		return NULL;
+	else
+		return Io_fappend(io, f, s);
+}
+
+static struct Io *Io_fremove(struct Io *io, FILE *f);
+static FILE *Io_nextfile(struct Io *io, FILE *f);
+
+static int
+Io_fputc(struct Io *io, int c){
+	FILE *f;
+	FILE *lf;
+	char *ln;
+
+	f = NULL;
+	lf = NULL;
+	while((f = Io_nextfile(io, f)) != NULL){
+		if(lf != NULL){
+			if(fclose(lf) == EOF)
+				fprintf(stderr, "%s: %s: %s\n",
+					program_name, ln, strerror(errno));
+			Io_fremove(io, lf);
+			if(io->s == 0)
+				return EOF;
+			lf = NULL;
+		}
+		if(putc(c, f) == EOF){
+			lf = f;
+			ln = Io_filename(io, lf);
+		}
+	}
+
+	return c;
+}
+
+static struct Io *
+Io_fremove(struct Io *io, FILE *f){
+	size_t i;
+
+	for(i = 0; i < io->s && io->files[i] != f; ++i);
+	if(io->files[i] == f){
+		for( ; i < io->s - 1; ++i){
+			io->files[i] = io->files[i + 1];
+			io->names[i] = io->names[i + 1];
+		}
+		if(io->ex->s > 0){
+			io->files[io->s] = io->ex->files[0];
+			io->names[io->s] = io->ex->names[0];
+		}else{
+			--io->s;
+			return io;
+		}
+		i = 0;
+	}else{
+		for(i = 0; i < io->ex->s && io->ex->files[i] != f; ++i);
+		if(io->ex->files[i] != f)
+			return NULL;
+	}
+
+	for( ; i < io->ex->s - 1; ++i){
+		io->ex->files[i] = io->ex->files[i + 1];
+		io->ex->names[i] = io->ex->names[i + 1];
+	}
+	--io->ex->s;
+
+	return io;
+}
+
+static FILE *
+Io_nextfile(struct Io *io, FILE *f){
+	size_t i;
+
+	if(f == NULL)
+		return io->files[0];
+
+	for(i = 0; i < io->s; ++i)
+		if(io->files[i] == f){
+			if(i == io->s - 1 && io->ex->s == 0)
+				return NULL;
+			else if(i == io->s - 1)
+				return io->ex->files[0];
+			else
+				return io->files[i + 1];
+		}
+	for(i = 0; i < io->ex->s; ++i)
+		if(io->ex->files[i] == f){
+			if(i == io->ex->s - 1)
+				break;
+			else
+				return io->ex->files[i + 1];
+		}
+
+	return NULL;
+}
+
+static struct Io *
+Io_unbuffer(struct Io *io){
+	size_t i;
+
+	for(i = 0; i < io->s; ++i)
+		setvbuf(io->files[i], NULL, _IONBF, 0);
+
+	for(i = 0; i < io->ex->s; ++i)
+		setvbuf(io->ex->files[i], NULL, _IONBF, 0);
+	
+	return io;
+}
+
+static int
+oserr(char *s, char *r){
+
+	fprintf(stderr, "%s: %s: %s\n", s, r, strerror(errno));
+
+	return EX_OSERR;
+}
+
+static int
+usage(char *s){
+
+	fprintf(stderr, "Usage: %s (-ehu) (-i [input])... (-o [output])...\n",
+		s);
+
+	return EX_USAGE;
+}
+
+int main(int argc, char *argv[]){
+	int c;
+	FILE *f;
+	size_t i;
+	struct Io io[2]; /* {read, write, error} */
+	struct Io_ex io_ex[2];
+	FILE *lf;
+	char *ln;
+	char unbuffered;
+
+	if(argc < 2){ /* simple invocation */
+		while((c = getc(stdin)) != EOF)
+			if(putc(c, stdout) == EOF)
+				break;
+		return EX_OK;
+	}
+
+	io[0].ex = &io_ex[0];
+	io[1].ex = &io_ex[1];
+	Io_construct(&io[0]);
+	Io_construct(&io[1]);
+	io[0].fmode = rmode;
+	io[1].fmode = wmode;
+
+	Io_fappend(&io[0], stdin, stdin_name);
+	Io_fappend(&io[1], stdout, stdout_name);
+	io[0].s = -1;
+	io[1].s = -1;
+
+	unbuffered = 0;
+
+	while((c = getopt(argc, argv, "ehi:o:u")) != -1)
+		switch(c){
+		case 'e':
+			Io_fappend(&io[1], stderr, stderr_name);
+			break;
+		case 'i': case 'o':
+			if(optarg[0] == '-' && optarg[1] == '\0'){
+				/* "-" */
+				Io_fappend(&io[c == 'o'],
+					c == 'i' ? stdin : stdout,
+					c == 'i' ? stdin_name : stdout_name);
+				break;
+			}else if(Io_fopen(&io[c == 'o'], optarg)
+					!= NULL)
+				break;
+			/* does not exist, so try to create it */
+			if(c == 'o' && errno == ENOENT){
+				io[1].fmode = wharsh;
+				if(Io_fopen(&io[1], optarg) != NULL){
+					io[1].fmode = wmode;
+					break;
+				}
+			}
+			terminate(io);
+			return oserr(argv[0], optarg);;
+		case 'u':
+			unbuffered = 1;
+			break;
+		default:
+			terminate(io);
+			return usage(argv[0]);
+		}
+
+	if(unbuffered){
+		Io_unbuffer(&io[0]);
+		Io_unbuffer(&io[1]);
+	}
+
+	if(io[0].s == -1)
+		io[0].s = 1;
+	if(io[1].s == -1)
+		io[1].s = 1;
+
+	lf = NULL;
+	
+	for(i = 0; i < io[0].s; ++i){
+		while((c = getc(io[0].files[i])) != EOF)
+			if(Io_fputc(&io[1], c) == EOF){ /* notebook's full */
+				terminate(io);
+				return EX_OK;
+			}
+	}
+
+	terminate(io);
+
+	return EX_OK;
+}