From bc94551f63cfc4c05a56628dfcb386707d9e98cb Mon Sep 17 00:00:00 2001
From: Richard Russon <rich@flatcap.org>
Date: Sat, 26 Sep 2015 14:22:26 +0100
Subject: head,tail: add the -z,--zero-terminated option

* doc/coreutils.texi: Reference the option description.
* src/head.c: Parameterize the delimiter character.
* src/tail.c: Likewise.
* tests/misc/head.pl: Add test case.
* tests/misc/tail.pl: Likewise.
* NEWS: Mention the new feature.
---
 src/tail.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

(limited to 'src/tail.c')

diff --git a/src/tail.c b/src/tail.c
index 9007888fc..781adf200 100644
--- a/src/tail.c
+++ b/src/tail.c
@@ -180,6 +180,9 @@ static bool from_start;
 /* If true, print filename headers.  */
 static bool print_headers;
 
+/* Character to split lines by. */
+static char line_end;
+
 /* When to print the filename banners.  */
 enum header_mode
 {
@@ -238,6 +241,7 @@ static struct option const long_options[] =
   {"silent", no_argument, NULL, 'q'},
   {"sleep-interval", required_argument, NULL, 's'},
   {"verbose", no_argument, NULL, 'v'},
+  {"zero-terminated", no_argument, NULL, 'z'},
   {GETOPT_HELP_OPTION_DECL},
   {GETOPT_VERSION_OPTION_DECL},
   {NULL, 0, NULL, 0}
@@ -296,6 +300,9 @@ With more than one FILE, precede each with a header giving the file name.\n\
                              with inotify and --pid=P, check process P at\n\
                              least once every N seconds\n\
   -v, --verbose            always output headers giving file names\n\
+"), stdout);
+     fputs (_("\
+  -z, --zero-terminated    line delimiter is NUL, not newline\n\
 "), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
@@ -499,7 +506,7 @@ file_lines (const char *pretty_filename, int fd, uintmax_t n_lines,
   *read_pos = pos + bytes_read;
 
   /* Count the incomplete line on files that don't end with a newline.  */
-  if (bytes_read && buffer[bytes_read - 1] != '\n')
+  if (bytes_read && buffer[bytes_read - 1] != line_end)
     --n_lines;
 
   do
@@ -510,7 +517,7 @@ file_lines (const char *pretty_filename, int fd, uintmax_t n_lines,
       while (n)
         {
           char const *nl;
-          nl = memrchr (buffer, '\n', n);
+          nl = memrchr (buffer, line_end, n);
           if (nl == NULL)
             break;
           n = nl - buffer;
@@ -595,7 +602,7 @@ pipe_lines (const char *pretty_filename, int fd, uintmax_t n_lines,
       {
         char const *buffer_end = tmp->buffer + n_read;
         char const *p = tmp->buffer;
-        while ((p = memchr (p, '\n', buffer_end - p)))
+        while ((p = memchr (p, line_end, buffer_end - p)))
           {
             ++p;
             ++tmp->nlines;
@@ -649,7 +656,7 @@ pipe_lines (const char *pretty_filename, int fd, uintmax_t n_lines,
     goto free_lbuffers;
 
   /* Count the incomplete line on files that don't end with a newline.  */
-  if (last->buffer[last->nbytes - 1] != '\n')
+  if (last->buffer[last->nbytes - 1] != line_end)
     {
       ++last->nlines;
       ++total_lines;
@@ -671,7 +678,7 @@ pipe_lines (const char *pretty_filename, int fd, uintmax_t n_lines,
         size_t j;
         for (j = total_lines - n_lines; j; --j)
           {
-            beg = memchr (beg, '\n', buffer_end - beg);
+            beg = memchr (beg, line_end, buffer_end - beg);
             assert (beg);
             ++beg;
           }
@@ -857,7 +864,7 @@ start_lines (const char *pretty_filename, int fd, uintmax_t n_lines,
       *read_pos += bytes_read;
 
       char *p = buffer;
-      while ((p = memchr (p, '\n', buffer_end - p)))
+      while ((p = memchr (p, line_end, buffer_end - p)))
         {
           ++p;
           if (--n_lines == 0)
@@ -2047,7 +2054,7 @@ parse_options (int argc, char **argv,
 {
   int c;
 
-  while ((c = getopt_long (argc, argv, "c:n:fFqs:v0123456789",
+  while ((c = getopt_long (argc, argv, "c:n:fFqs:vz0123456789",
                            long_options, NULL))
          != -1)
     {
@@ -2124,6 +2131,10 @@ parse_options (int argc, char **argv,
           *header_mode = always;
           break;
 
+        case 'z':
+          line_end = '\0';
+          break;
+
         case_GETOPT_HELP_CHAR;
 
         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
@@ -2221,6 +2232,7 @@ main (int argc, char **argv)
 
   count_lines = true;
   forever = from_start = print_headers = false;
+  line_end = '\n';
   obsolete_option = parse_obsolete_option (argc, argv, &n_units);
   argc -= obsolete_option;
   argv += obsolete_option;
-- 
cgit v1.2.3-54-g00ecf