zsh-workers
 help / color / mirror / code / Atom feed
From: Peter Stephenson <p.stephenson@samsung.com>
To: "zsh-workers@zsh.org" <zsh-workers@zsh.org>
Subject: Re: Feature request: ZSH_XTRACEFD variable
Date: Tue, 13 Aug 2019 15:38:27 +0000	[thread overview]
Message-ID: <1565710707.5633.11.camel@samsung.com> (raw)
In-Reply-To: <CAD8ZDTokqOTfEajquX2SKU5pLWgd85sPdRMYkxE4nF0pQhi+BA@mail.gmail.com>

How about this?

I've tried to make it so that if the fd is 2 or less it always uses
the standard file, if it's greater it always creates or frees one, and
it only creates a new file when it's requested to switch.

One other fix is that we only need to fclose(xtrerr) which then closes
the file descriptor.  There's no way of just closing the file and not
the file descriptor --- we'll need to document that the file descriptor
is closed if ZSH_XTRACEFD changes again since it's a bit illogical given
that the user opened the fd in the first place.

pws

diff --git a/Src/exec.c b/Src/exec.c
index e81053d67..fe702b644 100644
--- a/Src/exec.c
+++ b/Src/exec.c
@@ -5394,7 +5394,7 @@ execshfunc(Shfunc shf, LinkList args)
     cmdsp = 0;
     if ((osfc = sfcontext) == SFC_NONE)
 	sfcontext = SFC_DIRECT;
-    xtrerr = stderr;
+    xtrerr = xtrace_file;
 
     doshfunc(shf, args, 0);
 
diff --git a/Src/init.c b/Src/init.c
index 445cd3937..c51197079 100644
--- a/Src/init.c
+++ b/Src/init.c
@@ -609,8 +609,10 @@ init_io(char *cmd)
 	SHTTY = -1;
     }
 
-    /* Send xtrace output to stderr -- see execcmd() */
-    xtrerr = stderr;
+    /* Send xtrace output to zsh_xtracefd file descriptor -- see execcmd() */
+    if (zsh_xtracefd == 0)
+	zsh_xtracefd = 2;
+    xtracefdassign();
 
     /* Make sure the tty is opened read/write. */
     if (isatty(0)) {
diff --git a/Src/params.c b/Src/params.c
index 1499e3a40..2347ee9c3 100644
--- a/Src/params.c
+++ b/Src/params.c
@@ -102,7 +102,8 @@ zlong lastval,		/* $?           */
      zterm_lines,	/* $LINES       */
      rprompt_indent,	/* $ZLE_RPROMPT_INDENT */
      ppid,		/* $PPID        */
-     zsh_subshell;	/* $ZSH_SUBSHELL */
+     zsh_subshell,	/* $ZSH_SUBSHELL */
+     zsh_xtracefd;	/* $ZSH_XTRACEFD */
 
 /* $FUNCNEST    */
 /**/
@@ -264,6 +265,9 @@ static const struct gsu_array pipestatus_gsu =
 static const struct gsu_integer rprompt_indent_gsu =
 { intvargetfn, zlevarsetfn, rprompt_indent_unsetfn };
 
+static const struct gsu_integer xtracefd_gsu =
+{ intvargetfn, xtracefdsetfn, xtracefdunsetfn };
+
 /* Nodes for special parameters for parameter hash table */
 
 #ifdef HAVE_UNION_INIT
@@ -353,6 +357,7 @@ IPDEF5("LINES", &zterm_lines, zlevar_gsu),
 IPDEF5U("ZLE_RPROMPT_INDENT", &rprompt_indent, rprompt_indent_gsu),
 IPDEF5("SHLVL", &shlvl, varinteger_gsu),
 IPDEF5("FUNCNEST", &zsh_funcnest, varinteger_gsu),
+IPDEF5("ZSH_XTRACEFD", &zsh_xtracefd, xtracefd_gsu),
 
 /* Don't import internal integer status variables. */
 #define IPDEF6(A,B,F) {{NULL,A,PM_INTEGER|PM_SPECIAL|PM_DONTIMPORT},BR((void *)B),GSU(F),10,0,NULL,NULL,NULL,0}
@@ -4387,6 +4392,71 @@ setsecondstype(Param pm, int on, int off)
     return 0;
 }
 
+/* Open / assign the XTRACE fd */
+
+/**/
+void xtracefdassign(void)
+{
+    int fd = (int)zsh_xtracefd;
+    switch (fd)
+    {
+    case 0:			/* bizarre, but handle for consistency */
+	xtrerr = stdin;
+	break;
+
+    case 1:
+	xtrerr = stdout;
+	break;
+
+    case 2:
+	xtrerr = stderr;
+	break;
+
+    default:
+	xtrerr = fdopen(fd, "w");
+	break;
+    }
+    xtrace_file = xtrerr;
+}
+
+/* Function to set value of special parameter `ZSH_XTRACEFD' */
+
+/**/
+void
+xtracefdsetfn(Param pm, zlong fd)
+{
+    int current_fd;
+
+    /* Check that the given file descriptor is valid */
+    if (fcntl(fd, F_GETFD) != -1 || errno != EBADF) {
+      current_fd = intvargetfn(pm);
+      /* We never close file descriptors 0 (stdin), 1 (stdout) or 2 stderr) */
+      if (current_fd > 2)
+        fclose(xtrerr);
+      intvarsetfn(pm, fd);
+      xtracefdassign();
+    } else
+      zwarn("file descriptor %d is not valid", fd);
+
+}
+
+/* Function to unset value of special parameter `ZSH_XTRACEFD' */
+
+/**/
+void
+xtracefdunsetfn(Param pm, UNUSED(int exp))
+{
+    int current_fd = intvargetfn(pm);
+    if (current_fd == 2)  /* Nothing to do, already using stderr */
+      return;
+    else {  /* Reset to file descriptor 2 (stderr) */
+      intvarsetfn(pm, 2);
+      if (current_fd > 2)
+	  fclose(xtrerr);  /* Never close standard descriptors */
+      xtrerr = xtrace_file = stderr;
+    }
+}
+
 /* Function to get value for special parameter `USERNAME' */
 
 /**/
diff --git a/Src/utils.c b/Src/utils.c
index 46cf7bcf6..2eee27697 100644
--- a/Src/utils.c
+++ b/Src/utils.c
@@ -1760,12 +1760,19 @@ checkmailpath(char **s)
 /**/
 FILE *xtrerr = 0;
 
+/* This records the last file XTRACE was open too.
+ * It's used for restoring XTRACE after a possible redirection.gggg
+ */
+
+/**/
+FILE *xtrace_file;
+
 /**/
 void
 printprompt4(void)
 {
     if (!xtrerr)
-	xtrerr = stderr;
+	xtracefdassign();
     if (prompt4) {
 	int l, t = opts[XTRACE];
 	char *s = dupstring(prompt4);

  parent reply	other threads:[~2019-08-13 15:39 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-17 15:08 Timothée Mazzucotelli
2019-05-18  7:55 ` Stephane Chazelas
2019-05-20 10:34   ` Stephane Chazelas
2019-07-21 15:08     ` Timothée Mazzucotelli
2019-07-21 15:22       ` Peter Stephenson
2019-07-31 19:40         ` Timothée Mazzucotelli
2019-07-31 19:45           ` Timothée Mazzucotelli
2019-07-31 21:12             ` Sebastian Gniazdowski
2019-08-13  9:14           ` Peter Stephenson
2019-08-13 15:38           ` Peter Stephenson [this message]
2019-09-10 22:19             ` Timothée Mazzucotelli
2019-09-11  8:45               ` Peter Stephenson
2020-04-19 10:30             ` Timothée Mazzucotelli
2020-04-20 14:09               ` Peter Stephenson
2020-05-02 18:02                 ` Timothée Mazzucotelli
2020-05-02 21:15                   ` Bart Schaefer
2020-05-03  0:06                     ` Daniel Shahaf
2020-05-03  4:43                       ` Roman Perepelitsa
2020-05-03 16:21                         ` Daniel Shahaf
2020-05-03 19:54                         ` Peter Stephenson
2020-05-03 21:06                           ` Daniel Shahaf
2020-05-04  8:35                             ` Peter Stephenson
2020-05-05  0:03                               ` Daniel Shahaf
2020-05-05 16:36                                 ` Timothée Mazzucotelli
2020-05-05 16:47                                   ` Peter Stephenson
2020-05-05 22:19                                     ` Bart Schaefer
2020-09-03 13:51                                       ` Timothée Mazzucotelli
2020-09-04 19:48                                         ` Daniel Shahaf
2020-09-04 19:53                                           ` Bart Schaefer
2020-09-05  9:24                                             ` Timothée Mazzucotelli
2020-05-05 22:11                                   ` Bart Schaefer
2020-05-03  6:01                       ` Stephane Chazelas
2020-05-03  7:07                         ` Stephane Chazelas
2020-05-03 17:30                   ` Peter Stephenson
2020-05-03 21:23                     ` Daniel Shahaf
2020-05-04  8:26                       ` Peter Stephenson
2020-05-05 20:50               ` Daniel Shahaf

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1565710707.5633.11.camel@samsung.com \
    --to=p.stephenson@samsung.com \
    --cc=zsh-workers@zsh.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.vuxu.org/mirror/zsh/

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).