From 3e0e8c687eee4c292db106efab20f8e565549bf8 Mon Sep 17 00:00:00 2001
From: Rob Landley <rob@landley.net>
Date: Thu, 18 Jan 2024 16:42:42 -0600
Subject: [PATCH] Switch stdout default to block buffering, replace xflush()
 with xferror(), change xputs*() to fwrite() instead of write() but add a
 flush to maintain previous semantics. Then add flushes and TOYFLAG_LINEBUF
 until the test suite passes.

---
 lib/lib.h            |  2 +-
 lib/xwrap.c          | 19 +++++++++----------
 main.c               |  6 +++++-
 toys/net/httpd.c     |  2 +-
 toys/other/blkid.c   |  4 ++--
 toys/other/hexedit.c |  6 +++---
 toys/pending/getty.c |  3 +--
 toys/pending/sh.c    |  2 +-
 toys/pending/vi.c    |  6 ++++--
 toys/posix/head.c    |  2 +-
 toys/posix/tail.c    |  2 +-
 11 files changed, 29 insertions(+), 25 deletions(-)

diff --git a/lib/lib.h b/lib/lib.h
index 89e15f99..da20dd10 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -115,7 +115,7 @@ char *xstrndup(char *s, size_t n);
 char *xstrdup(char *s);
 void *xmemdup(void *s, long len);
 char *xmprintf(char *format, ...) printf_format;
-void xflush(int flush);
+void xferror(FILE *fp);
 void xprintf(char *format, ...) printf_format;
 void xputsl(char *s, int len);
 void xputsn(char *s);
diff --git a/lib/xwrap.c b/lib/xwrap.c
index c47276c4..d2e787e1 100644
--- a/lib/xwrap.c
+++ b/lib/xwrap.c
@@ -54,7 +54,7 @@ void xexit(void)
 
     free(al);
   }
-  xflush(1);
+  if (fflush(0) || ferror(stdout)) if (!toys.exitval) perror_msg("write");
   _xexit();
 }
 
@@ -143,10 +143,9 @@ char *xmprintf(char *format, ...)
 }
 
 // if !flush just check for error on stdout without flushing 
-void xflush(int flush)
+void xferror(FILE *fp)
 {
-  if ((flush && fflush(0)) || ferror(stdout))
-    if (!toys.exitval) perror_msg("write");
+  if (ferror(fp)) perror_exit("write");
 }
 
 void xprintf(char *format, ...)
@@ -156,14 +155,15 @@ void xprintf(char *format, ...)
 
   vprintf(format, va);
   va_end(va);
-  xflush(0);
+
+  if (ferror(stdout)) perror_exit("stdout");
 }
 
-// Put string with length (does not append newline)
+// Put string with length (does not append newline) with immediate flush
 void xputsl(char *s, int len)
 {
-  xflush(1);
-  xwrite(1, s, len);
+  fwrite(s, 1, len, stdout);
+  if (fflush(stdout) || ferror(stdout)) perror_exit("stdout"); 
 }
 
 // xputs with no newline
@@ -176,13 +176,12 @@ void xputsn(char *s)
 void xputs(char *s)
 {
   puts(s);
-  xflush(0);
+  xferror(stdout);
 }
 
 void xputc(char c)
 {
   if (EOF == fputc(c, stdout)) perror_exit("write");
-  xflush(0);
 }
 
 // daemonize via vfork(). Does not chdir("/"), caller should do that first
diff --git a/main.c b/main.c
index bb8377db..93cf768e 100644
--- a/main.c
+++ b/main.c
@@ -154,6 +154,8 @@ void check_help(char **arg)
 // Setup toybox global state for this command.
 void toy_singleinit(struct toy_list *which, char *argv[])
 {
+  char *buf;
+
   toys.which = which;
   toys.argv = argv;
   toys.toycount = ARRAY_LEN(toy_list);
@@ -176,7 +178,8 @@ void toy_singleinit(struct toy_list *which, char *argv[])
       uselocale(newlocale(LC_CTYPE_MASK, "C.UTF-8", 0) ? :
         newlocale(LC_CTYPE_MASK, "en_US.UTF-8", 0));
 
-    setvbuf(stdout, 0, (which->flags & TOYFLAG_LINEBUF) ? _IOLBF : _IONBF, 0);
+    buf = (which->flags & TOYFLAG_LINEBUF) ? 0 : xmalloc(4096);
+    setvbuf(stdout, buf, buf ? _IOFBF : _IOLBF, buf ? 4096 : 0);
   }
 }
 
@@ -291,6 +294,7 @@ void toybox_main(void)
 int main(int argc, char *argv[])
 {
   // don't segfault if our environment is crazy
+  // TODO mooted by kernel commit dcd46d897adb7 5.17 kernel Jan 2022
   if (!*argv) return 127;
 
   // Snapshot stack location so we can detect recursion depth later.
diff --git a/toys/net/httpd.c b/toys/net/httpd.c
index 3cb78421..845175dd 100644
--- a/toys/net/httpd.c
+++ b/toys/net/httpd.c
@@ -12,7 +12,7 @@
  * -ifv -p [IP:]PORT -u [USER][:GRP] -c CFGFILE
  * cgi: SERVER_PORT SERVER_NAME REMOTE_ADDR REMOTE_HOST REQUEST_METHOD
 
-USE_HTTPD(NEWTOY(httpd, ">1v", TOYFLAG_USR|TOYFLAG_BIN))
+USE_HTTPD(NEWTOY(httpd, ">1v", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_LINEBUF))
 
 config HTTPD
   bool "httpd"
diff --git a/toys/other/blkid.c b/toys/other/blkid.c
index e78f20d8..cdeb3a6f 100644
--- a/toys/other/blkid.c
+++ b/toys/other/blkid.c
@@ -5,8 +5,8 @@
  * See ftp://ftp.kernel.org/pub/linux/utils/util-linux/v2.24/libblkid-docs/api-index-full.html
  * TODO: -U and -L should require arguments
 
-USE_BLKID(NEWTOY(blkid, "ULo:s*[!LU]", TOYFLAG_BIN))
-USE_FSTYPE(NEWTOY(fstype, "<1", TOYFLAG_BIN))
+USE_BLKID(NEWTOY(blkid, "ULo:s*[!LU]", TOYFLAG_BIN|TOYFLAG_LINEBUF))
+USE_FSTYPE(NEWTOY(fstype, "<1", TOYFLAG_BIN|TOYFLAG_LINEBUF))
 
 config BLKID
   bool "blkid"
diff --git a/toys/other/hexedit.c b/toys/other/hexedit.c
index 80631ac1..3a50ed9c 100644
--- a/toys/other/hexedit.c
+++ b/toys/other/hexedit.c
@@ -43,7 +43,7 @@ GLOBALS(
 static void show_error(char *what)
 {
   printf("\e[%dH\e[41m\e[37m\e[K\e[1m%s\e[0m", TT.rows+1, what);
-  xflush(1);
+  fflush(0);
   msleep(500);
 }
 
@@ -55,7 +55,7 @@ static int prompt(char *prompt, char *initial_value)
   strcpy(TT.input, initial_value);
   while (1) {
     printf("\e[%dH\e[K\e[1m%s: \e[0m%s\e[?25h", TT.rows+1, prompt, TT.input);
-    xflush(1);
+    fflush(0);
 
     key = scan_key(TT.keybuf, -1);
     if (key < 0 || key == 27) break;
@@ -252,7 +252,7 @@ void hexedit_main(void)
 
     // Display cursor and flush output
     highlight(x, y, FLAG(r) ? 3 : side);
-    xflush(1);
+    fflush(0);
 
     // Wait for next key
     key = scan_key(TT.keybuf, -1);
diff --git a/toys/pending/getty.c b/toys/pending/getty.c
index 8c93a250..2d68b160 100644
--- a/toys/pending/getty.c
+++ b/toys/pending/getty.c
@@ -166,8 +166,7 @@ static int read_login_name(void)
 
     if (!FLAG(i)) write_issue(TT.f, &uts);
 
-    printf("%s login: ", uts.nodename);
-    xflush(1);
+    dprintf(1, "%s login: ", uts.nodename);
 
     TT.buff[0] = getchar();
     if (!TT.buff[0] && TT.sc > 1) return 0; // Switch speed
diff --git a/toys/pending/sh.c b/toys/pending/sh.c
index 37c2052d..27dab14e 100644
--- a/toys/pending/sh.c
+++ b/toys/pending/sh.c
@@ -2891,7 +2891,7 @@ static struct sh_process *run_command(void)
 //dprintf(2, "%d builtin", getpid()); for (int xx = 0; xx<=pp->arg.c; xx++) dprintf(2, "{%s}", pp->arg.v[xx]); dprintf(2, "\n");
         toy_singleinit(tl, pp->arg.v);
         tl->toy_main();
-        xflush(0);
+        xexit();
       }
       toys.rebound = 0;
       pp->exit = toys.exitval;
diff --git a/toys/pending/vi.c b/toys/pending/vi.c
index 2a5e4cab..44a22a5e 100644
--- a/toys/pending/vi.c
+++ b/toys/pending/vi.c
@@ -548,7 +548,8 @@ static void show_error(char *fmt, ...)
   vprintf(fmt, va);
   va_end(va);
   printf("\e[0m");
-  xflush(1);
+  fflush(0);
+  xferror(stdout);
 
   // TODO: better integration with status line: keep
   // message until next operation.
@@ -1619,7 +1620,8 @@ static void draw_page()
   printf("\e[%u;%uH%s\e[%u;%uH", TT.screen_height+1,
     (int) (1+TT.screen_width-strlen(toybuf)),
     toybuf, cy_scr+1, cx_scr+1);
-  xflush(1);
+  fflush(0);
+  xferror(stdout);
 }
 
 void vi_main(void)
diff --git a/toys/posix/head.c b/toys/posix/head.c
index 04e1658c..58da35a0 100644
--- a/toys/posix/head.c
+++ b/toys/posix/head.c
@@ -6,7 +6,7 @@
  *
  * Deviations from posix: -c
 
-USE_HEAD(NEWTOY(head, "?n(lines)#<0=10c(bytes)#<0qv[-nc]", TOYFLAG_USR|TOYFLAG_BIN))
+USE_HEAD(NEWTOY(head, "?n(lines)#<0=10c(bytes)#<0qv[-nc]", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_LINEBUF))
 
 config HEAD
   bool "head"
diff --git a/toys/posix/tail.c b/toys/posix/tail.c
index 514bd5b8..1b17fcd5 100644
--- a/toys/posix/tail.c
+++ b/toys/posix/tail.c
@@ -6,7 +6,7 @@
  *
  * Deviations from posix: -f waits for pipe/fifo on stdin (nonblock?).
 
-USE_TAIL(NEWTOY(tail, "?fFs:c(bytes)-n(lines)-[-cn][-fF]", TOYFLAG_USR|TOYFLAG_BIN))
+USE_TAIL(NEWTOY(tail, "?fFs:c(bytes)-n(lines)-[-cn][-fF]", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_LINEBUF))
 
 config TAIL
   bool "tail"
-- 
2.39.2