Factor out equivalent code from ttyread/ttysend

The echo-to-terminal portions of ttyread and ttysend were actually doing
the same thing.  New function twrite() now handles this.  The parameter
show_ctrl determines whether control characters are shown as "^A".  This
was the only difference between tputc and techo, and techo is now unused
and removed.

(This commit should not change st's behaviour.)

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>

2 files changed, 41 insertions, 62 deletions

diff --git a/st.c b/st.c
index 58f7941..641f896 100644
--- a/st.c
+++ b/st.c
@@ -161,8 +161,8 @@ static void tsetchar(Rune, Glyph *, int, int);
 static void tsetscroll(int, int);
 static void tswapscreen(void);
 static void tsetmode(int, int, int *, int);
+static int twrite(const char *, int, int);
 static void tfulldirt(void);
-static void techo(Rune);
 static void tcontrolcode(uchar );
 static void tdectest(char );
 static void tdefutf8(char);
@@ -254,7 +254,7 @@ xstrdup(char *s)
 }
 
 size_t
-utf8decode(char *c, Rune *u, size_t clen)
+utf8decode(const char *c, Rune *u, size_t clen)
 {
         size_t i, j, len, type;
         Rune udecoded;
@@ -768,38 +768,19 @@ ttyread(void)
 {
         static char buf[BUFSIZ];
         static int buflen = 0;
-        char *ptr;
-        int charsize; /* size of utf8 char in bytes */
-        Rune unicodep;
+        int written;
         int ret;
 
         /* append read bytes to unprocessed bytes */
         if ((ret = read(cmdfd, buf+buflen, LEN(buf)-buflen)) < 0)
                 die("Couldn't read from shell: %s\n", strerror(errno));
-
         buflen += ret;
-        ptr = buf;
 
-        for (;;) {
-                if (IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
-                        /* process a complete utf8 char */
-                        charsize = utf8decode(ptr, &unicodep, buflen);
-                        if (charsize == 0)
-                                break;
-                        tputc(unicodep);
-                        ptr += charsize;
-                        buflen -= charsize;
-
-                } else {
-                        if (buflen <= 0)
-                                break;
-                        tputc(*ptr++ & 0xFF);
-                        buflen--;
-                }
-        }
+        written = twrite(buf, buflen, 0);
+        buflen -= written;
         /* keep any uncomplete utf8 char for the next call */
         if (buflen > 0)
-                memmove(buf, ptr, buflen);
+                memmove(buf, buf + written, buflen);
 
         return ret;
 }
@@ -864,27 +845,9 @@ write_error:
 void
 ttysend(char *s, size_t n)
 {
-        int len;
-        char *t, *lim;
-        Rune u;
-
         ttywrite(s, n);
-        if (!IS_SET(MODE_ECHO))
-                return;
-
-        lim = &s[n];
-        for (t = s; t < lim; t += len) {
-                if (IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
-                        len = utf8decode(t, &u, n);
-                } else {
-                        u = *t & 0xFF;
-                        len = 1;
-                }
-                if (len <= 0)
-                        break;
-                techo(u);
-                n -= len;
-        }
+        if (IS_SET(MODE_ECHO))
+                twrite(s, n, 1);
 }
 
 void
@@ -2032,22 +1995,6 @@ tputtab(int n)
 }
 
 void
-techo(Rune u)
-{
-        if (ISCONTROL(u)) { /* control code */
-                if (u & 0x80) {
-                        u &= 0x7f;
-                        tputc('^');
-                        tputc('[');
-                } else if (u != '\n' && u != '\r' && u != '\t') {
-                        u ^= 0x40;
-                        tputc('^');
-                }
-        }
-        tputc(u);
-}
-
-void
 tdefutf8(char ascii)
 {
         if (ascii == 'G')
@@ -2437,6 +2384,38 @@ check_control_code:
         }
 }
 
+int
+twrite(const char *buf, int buflen, int show_ctrl)
+{
+        int charsize;
+        Rune u;
+        int n;
+
+        for (n = 0; n < buflen; n += charsize) {
+                if (IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
+                        /* process a complete utf8 char */
+                        charsize = utf8decode(buf + n, &u, buflen - n);
+                        if (charsize == 0)
+                                break;
+                } else {
+                        u = buf[n] & 0xFF;
+                        charsize = 1;
+                }
+                if (show_ctrl && ISCONTROL(u)) {
+                        if (u & 0x80) {
+                                u &= 0x7f;
+                                tputc('^');
+                                tputc('[');
+                        } else if (u != '\n' && u != '\r' && u != '\t') {
+                                u ^= 0x40;
+                                tputc('^');
+                        }
+                }
+                tputc(u);
+        }
+        return n;
+}
+
 void
 tresize(int col, int row)
 {
diff --git a/st.h b/st.h
index 09473c2..3d9b6e7 100644
--- a/st.h
+++ b/st.h
@@ -209,7 +209,7 @@ void selnormalize(void);
 int selected(int, int);
 char *getsel(void);
 
-size_t utf8decode(char *, Rune *, size_t);
+size_t utf8decode(const char *, Rune *, size_t);
 size_t utf8encode(Rune, char *);
 
 void *xmalloc(size_t);