add select(2)-based i/o multiplexing

[st.git] / std.c

diff --git a/std.c b/std.c
index a7b2f4a..fbabaa4 100644 (file)
--- a/std.c
+++ b/std.c
@@ -16,6 +16,7 @@
 
 void buffer(char c);
 void cmd(const char *cmdstr, ...);
+int getch();
 void getpty(void);
 void movea(int x, int y);
 void mover(int x, int y);
@@ -24,6 +25,7 @@ void scroll(int l);
 void shell(void);
 void sigchld(int n);
 char unbuffer(void);
+void ungetch(int c);
 
 typedef struct {
        unsigned char data[BUFSIZ];
@@ -31,14 +33,19 @@ typedef struct {
        int n;
 } RingBuffer;
 
+typedef struct {
+       unsigned char data[BUFSIZ];
+       int i, n;
+} ReadBuffer;
+
 int cols = 80, lines = 25;
 int cx = 0, cy = 0;
 int c;
-FILE *fptm = NULL;
 int ptm, pts;
 _Bool bold, digit, qmark;
 pid_t pid;
 RingBuffer buf;
+ReadBuffer rbuf;
 
 void
 buffer(char c) {
@@ -61,6 +68,17 @@ cmd(const char *cmdstr, ...) {
        va_end(ap);
 }
 
+int
+getch() {
+       if(rbuf.i++ >= rbuf.n) {
+               rbuf.n = read(ptm, rbuf.data, LENGTH(rbuf.data));
+               if(rbuf.n == -1)
+                       eprintn("error, cannot read from slave pty");
+               rbuf.i = 0;
+       }
+       return rbuf.data[rbuf.i];
+}
+
 void
 movea(int x, int y) {
        x = MAX(x, cols);
@@ -81,10 +99,10 @@ parseesc(void) {
        int arg[16];
 
        memset(arg, 0, LENGTH(arg));
-       c = getc(fptm);
+       c = getch();
        switch(c) {
        case '[':
-               c = getc(fptm);
+               c = getch();
                for(j = 0; j < LENGTH(arg);) {
                        if(isdigit(c)) {
                                digit = 1;
@@ -106,7 +124,7 @@ parseesc(void) {
                                }
                                break;
                        }
-                       c = getc(fptm);
+                       c = getch();
                }
                switch(c) {
                case '@':
@@ -180,7 +198,7 @@ parseesc(void) {
                break;
        default:
                putchar('\033');
-               ungetc(c, fptm);
+               ungetch(c);
        }
 }
 
@@ -236,25 +254,41 @@ unbuffer(void) {
        return c;
 }
 
+void
+ungetch(int c) {
+       if(rbuf.i + 1 >= rbuf.n)
+               eprint("error, read buffer full\n");
+       rbuf.data[rbuf.i++] = c;
+}
+
 int
 main(int argc, char *argv[]) {
+       fd_set rfds;
+       int r;
+
        if(argc == 2 && !strcmp("-v", argv[1]))
                eprint("std-"VERSION", © 2008 Matthias-Christian Ott\n");
        else if(argc == 1)
                eprint("usage: st [-v]\n");
        getpty();
        shell();
-       fptm = fdopen(ptm, "r+");
-       if(!fptm)
-               eprintn("cannot open slave pty");
+       FD_ZERO(&rfds);
+       FD_SET(STDIN_FILENO, &rfds);
+       FD_SET(ptm, &rfds);
        for(;;) {
-               c = getc(fptm);
-               switch(c) {
-               case '\033':
-                       parseesc();
-                       break;
-               default:
-                       putchar(c);
+               r = select(ptm + 1, &rfds, NULL, NULL, NULL);
+               if(r == -1)
+                       eprintn("error, cannot select");
+               if(FD_ISSET(ptm, &rfds)) {
+                       c = getch();
+                       switch(c) {
+                       case '\033':
+                               parseesc();
+                               break;
+                       default:
+                               putchar(c);
+                       }
+                       fflush(stdout);
                }
        }
        return 0;