Re: sed: getting at the current file name

[Ralf Wildenhues]

* Ralf Wildenhues wrote on Sat, Nov 14, 2009 at 01:23:01PM CET:
> With --separate and a way to print the current file name we could
> replace the shell loop with two sed invocations.  For example, if a
> command `F' would print the file name of the currently open file or `-',
> plus a newline, then one could use:
[...]

Proposed patch, still lacking tests.  F is a bit unsymmetric to = wrt.
missing --separate, not sure how to change that; take the name of the
first input file only?

Cheers,
Ralf

>From 5131e412d337b225f9df3bb49adf62a72d6cf85e Mon Sep 17 00:00:00 2001
From: Ralf Wildenhues <address@hidden>
Date: Sun, 15 Nov 2009 20:11:21 +0100
Subject: [PATCH] New F command to print input file name

2009-11-15  Ralf Wildenhues  <address@hidden>

        * doc/sed.texi (Extended Commands): Document F command.
        * doc/sed-in.texi: Regenerate.
        * sed/compile.c (compile_program): Accept 'F' if not --posix.
        * sed/execute.c (open_next_file): Always initialize in_file_name.
        (execute_program): Handle 'F'.
        * NEWS: Update.
---
 NEWS            |    2 ++
 doc/sed-in.texi |    7 +++++++
 doc/sed.texi    |    7 +++++++
 sed/compile.c   |    3 ++-
 sed/execute.c   |   18 +++++++++++++-----
 5 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/NEWS b/NEWS
index b34758b..085e758 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,8 @@ Sed 4.2.2
 
 * -u also does unbuffered input, rather than unbuffered output only
 
+* New command `F' to print current input file name
+
 ----------------------------------------------------------------------------
 Sed 4.2.1
 
diff --git a/doc/sed-in.texi b/doc/sed-in.texi
index 0e64b23..eb48062 100644
--- a/doc/sed-in.texi
+++ b/doc/sed-in.texi
@@ -1400,6 +1400,13 @@ lines, all but the last ending with a back-slash.
 In both cases, the results are undefined if the command to be
 executed contains a @sc{nul} character.
 
address@hidden F
address@hidden F (File name) command
address@hidden Printing file name
address@hidden File name, printing
+Print out the file name of the current input file (with a trailing
+newline).
+
 @item L @var{n}
 @findex L (fLow paragraphs) command
 @cindex Reformat pattern space
diff --git a/doc/sed.texi b/doc/sed.texi
index 66a926e..83d9b8c 100644
--- a/doc/sed.texi
+++ b/doc/sed.texi
@@ -1401,6 +1401,13 @@ lines, all but the last ending with a back-slash.
 In both cases, the results are undefined if the command to be
 executed contains a @sc{nul} character.
 
address@hidden F
address@hidden F (File name) command
address@hidden Printing file name
address@hidden File name, printing
+Print out the file name of the current input file (with a trailing
+newline).
+
 @item L @var{n}
 @findex L (fLow paragraphs) command
 @cindex Reformat pattern space
diff --git a/sed/compile.c b/sed/compile.c
index c4a5250..9e9364d 100644
--- a/sed/compile.c
+++ b/sed/compile.c
@@ -1097,7 +1097,7 @@ compile_program(vector)
       if (posixicity == POSIXLY_BASIC)
        switch (ch)
          {
-           case 'e': case 'v': case 'z': case 'L':
+           case 'e': case 'F': case 'v': case 'z': case 'L':
            case 'Q': case 'T': case 'R': case 'W':
              bad_command(ch);
 
@@ -1230,6 +1230,7 @@ compile_program(vector)
        case '=':
        case 'd':
        case 'D':
+       case 'F':
        case 'g':
        case 'G':
        case 'h':
diff --git a/sed/execute.c b/sed/execute.c
index 28e520d..f9775ea 100644
--- a/sed/execute.c
+++ b/sed/execute.c
@@ -714,6 +714,12 @@ open_next_file(name, input)
 
   input->read_fn = read_file_line;
 
+  if (follow_symlinks)
+    input->in_file_name = follow_symlink (name);
+  else
+    input->in_file_name = name;
+
+
   if (in_place_extension)
     {
       int input_fd;
@@ -724,11 +730,6 @@ open_next_file(name, input)
       memset (&old_fscreatecon, 0, sizeof (old_fscreatecon));
 #endif
 
-      if (follow_symlinks)
-       input->in_file_name = follow_symlink (name);
-      else
-        input->in_file_name = name;
-
       /* get the base name */
       tmpdir = ck_strdup(input->in_file_name);
       if ((p = strrchr(tmpdir, '/')))
@@ -1758,6 +1759,13 @@ execute_program(vec, input)
               flush_output(output_file.fp);
              break;
 
+           case 'F':
+              output_missing_newline(&output_file);
+              fprintf(output_file.fp, "%s\n",
+                      input->in_file_name);
+              flush_output(output_file.fp);
+             break;
+
            default:
              panic("INTERNAL ERROR: Bad cmd %c", cur_cmd->cmd);
            }
-- 
1.6.5.1.31.gad12b