add description of std

[st.git] / std.c

diff --git a/std.c b/std.c
index ef9e57a..84a4b49 100644 (file)
--- a/std.c
+++ b/std.c
@@ -1,4 +1,16 @@
-/* See LICENSE file for copyright and license details. */
+/* See LICENSE file for copyright and license details.
+ *
+ * Simple terminal daemon is a terminal emulator. It can be used in
+ * combination with simple terminal to emulate a mostly VT100-compatible
+ * terminal.
+ * 
+ * In this process std works like a filter. It reads data from a
+ * pseudo-terminal and parses the escape sequences and transforms
+ * them into an ed(1)-like. The resulting data is buffered and written
+ * to stdout.
+ * Parallely it reads data from stdin and parses and executes the
+ * commands. The resulting data is written to the pseudo-terminal.
+ */

 #include <sys/types.h>
 #include <sys/wait.h>
 #include <ctype.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <ctype.h>


@@ -18,19 +30,6 @@
 #define MAX(a,b)       (((a) > (b)) ? (a) : (b))
 #define MIN(a,b)       (((a) < (b)) ? (a) : (b))
 
 #define MAX(a,b)       (((a) > (b)) ? (a) : (b))
 #define MIN(a,b)       (((a) < (b)) ? (a) : (b))
 

-static void buffer(char c);
-static void cmd(const char *cmdstr, ...);
-static int getch();
-static void getpty(void);
-static void movea(int x, int y);
-static void mover(int x, int y);
-static void parseesc(void);
-static void scroll(int l);
-static void shell(void);
-static void sigchld(int n);
-static char unbuffer(void);
-static void ungetch(int c);
-

 typedef struct {
        unsigned char data[BUFSIZ];
        int s, e;
 typedef struct {
        unsigned char data[BUFSIZ];
        int s, e;


@@ -40,8 +39,23 @@ typedef struct {
 typedef struct {
        unsigned char data[BUFSIZ];
        int i, n;
 typedef struct {
        unsigned char data[BUFSIZ];
        int i, n;

+       int fd;

 } ReadBuffer;
 
 } ReadBuffer;
 

+static void buffer(char c);
+static void cmd(const char *cmdstr, ...);
+static int getch(ReadBuffer *buf);
+static void getpty(void);
+static void movea(int x, int y);
+static void mover(int x, int y);
+static void parsecmd(void);
+static void parseesc(void);
+static void scroll(int l);
+static void shell(void);
+static void sigchld(int n);
+static char unbuffer(void);
+static void ungetch(ReadBuffer *buf, int c);
+

 static int cols = 80, lines = 25;
 static int cx = 0, cy = 0;
 static int c;
 static int cols = 80, lines = 25;
 static int cx = 0, cy = 0;
 static int c;


@@ -49,7 +63,7 @@ static int ptm, pts;
 static _Bool bold, digit, qmark;
 static pid_t pid;
 static RingBuffer buf;
 static _Bool bold, digit, qmark;
 static pid_t pid;
 static RingBuffer buf;

-static ReadBuffer rbuf;
+static ReadBuffer cmdbuf, ptmbuf;

 
 void
 buffer(char c) {
 
 void
 buffer(char c) {


@@ -73,14 +87,14 @@ cmd(const char *cmdstr, ...) {
 }
 
 int
 }
 
 int

-getch() {
-       if(rbuf.i++ >= rbuf.n) {
-               rbuf.n = read(ptm, rbuf.data, LENGTH(rbuf.data));
-               if(rbuf.n == -1)
-                       err(EXIT_FAILURE, "cannot read from slave pty");
-               rbuf.i = 0;
+getch(ReadBuffer *buf) {
+       if(buf->i++ >= buf->n) {
+               buf->n = read(buf->fd, buf->data, BUFSIZ);
+               if(buf->n == -1)
+                       err(EXIT_FAILURE, "cannot read");
+               buf->i = 0;

        }
        }

-       return rbuf.data[rbuf.i];
+       return buf->data[buf->i];

 }
 
 void
 }
 
 void


@@ -97,16 +111,20 @@ mover(int x, int y) {
        movea(cx + x, cy + y);
 }
 
        movea(cx + x, cy + y);
 }
 

+void
+parsecmd(void) {
+}
+

 void
 parseesc(void) {
        int i, j;
        int arg[16];
 
        memset(arg, 0, LENGTH(arg));
 void
 parseesc(void) {
        int i, j;
        int arg[16];
 
        memset(arg, 0, LENGTH(arg));

-       c = getch();
+       c = getch(&ptmbuf);

        switch(c) {
        case '[':
        switch(c) {
        case '[':

-               c = getch();
+               c = getch(&ptmbuf);

                for(j = 0; j < LENGTH(arg);) {
                        if(isdigit(c)) {
                                digit = 1;
                for(j = 0; j < LENGTH(arg);) {
                        if(isdigit(c)) {
                                digit = 1;


@@ -128,7 +146,7 @@ parseesc(void) {
                                }
                                break;
                        }
                                }
                                break;
                        }

-                       c = getch();
+                       c = getch(&ptmbuf);

                }
                switch(c) {
                case '@':
                }
                switch(c) {
                case '@':


@@ -202,7 +220,7 @@ parseesc(void) {
                break;
        default:
                putchar('\033');
                break;
        default:
                putchar('\033');

-               ungetch(c);
+               ungetch(&ptmbuf, c);

        }
 }
 
        }
 }
 


@@ -291,10 +309,10 @@ unbuffer(void) {
 }
 
 void
 }
 
 void

-ungetch(int c) {
-       if(rbuf.i + 1 >= rbuf.n)
-               errx(EXIT_FAILURE, "read buffer full");
-       rbuf.data[rbuf.i++] = c;
+ungetch(ReadBuffer *buf, int c) {
+       if(buf->i + 1 >= buf->n)
+               errx(EXIT_FAILURE, "buffer full");
+       buf->data[buf->i++] = c;

 }
 
 int
 }
 
 int


@@ -307,15 +325,28 @@ main(int argc, char *argv[]) {
                errx(EXIT_FAILURE, "usage: std [-v]");
        getpty();
        shell();
                errx(EXIT_FAILURE, "usage: std [-v]");
        getpty();
        shell();

+       cmdbuf.fd = STDIN_FILENO;
+       ptmbuf.fd = ptm;

        FD_ZERO(&rfds);
        FD_SET(STDIN_FILENO, &rfds);
        FD_SET(ptm, &rfds);
        for(;;) {
                if(select(ptm + 1, &rfds, NULL, NULL, NULL) == -1)
                        err(EXIT_FAILURE, "cannot select");
        FD_ZERO(&rfds);
        FD_SET(STDIN_FILENO, &rfds);
        FD_SET(ptm, &rfds);
        for(;;) {
                if(select(ptm + 1, &rfds, NULL, NULL, NULL) == -1)
                        err(EXIT_FAILURE, "cannot select");

+               if(FD_ISSET(STDIN_FILENO, &rfds))
+                       do {
+                               c = getch(&cmdbuf);
+                               switch(c) {
+                               case ':':
+                                       parsecmd();
+                                       break;
+                               default:
+                                       break;
+                               }
+                       } while(cmdbuf.i < cmdbuf.n);

                if(FD_ISSET(ptm, &rfds)) {
                        do {
                if(FD_ISSET(ptm, &rfds)) {
                        do {

-                               c = getch();
+                               c = getch(&ptmbuf);

                                switch(c) {
                                case '\033':
                                        parseesc();
                                switch(c) {
                                case '\033':
                                        parseesc();


@@ -323,7 +354,7 @@ main(int argc, char *argv[]) {
                                default:
                                        putchar(c);
                                }
                                default:
                                        putchar(c);
                                }

-                       } while(rbuf.i < rbuf.n);
+                       } while(ptmbuf.i < ptmbuf.n);

                        fflush(stdout);
                }
        }
                        fflush(stdout);
                }
        }