Add --group-separator and --no-group-separator to pcre2grep.

ChangeLog

@@ -155,15 +155,17 @@ consistency with OP_VREVERSE.
 40. In some legacy environments with a pre C99 snprintf, pcre2_regerror could
 return an incorrect value when the provided buffer was too small.
 
-41. Applied pull request #342 which adds sanity checks for ctype functions and 
+41. Applied pull request #342 which adds sanity checks for ctype functions and
 locks out any accidental sign-extension.
 
 42. In the 32-bit library, in non-UTF mode, a quantifier that followed a
-literal character with a value greater than or equal to 0x80000000u caused 
+literal character with a value greater than or equal to 0x80000000u caused
 undefined behaviour.
 
 43. \z was misbehaving when matching fragments inside invalid UTF strings.
 
+44. Implement --group-separator and --no-group-separator for pcre2grep.
+
 
 Version 10.42 11-December-2022
 ------------------------------

RunGrepTest

@@ -853,6 +853,14 @@ fi
 echo "---------------------------- Test 151 -----------------------------" >>testtrygrep
 (cd $srcdir; $valgrind $vjs $pcre2grep --colour=always -e this -e The -e 'The wo' testdata/grepinputv) >>testtrygrep
 
+echo "---------------------------- Test 152 -----------------------------" >>testtrygrep
+(cd $srcdir; $valgrind $vjs $pcre2grep -nA3 --group-separator='++' 'four' ./testdata/grepinputx) >>testtrygrep
+echo "RC=$?" >>testtrygrep
+
+echo "---------------------------- Test 153 -----------------------------" >>testtrygrep
+(cd $srcdir; $valgrind $vjs $pcre2grep -nA3 --no-group-separator 'four' ./testdata/grepinputx) >>testtrygrep
+echo "RC=$?" >>testtrygrep
+
 
 # Now compare the results.
 

doc/pcre2grep.1

@@ -1,4 +1,4 @@
-.TH PCRE2GREP 1 "08 February 2023" "PCRE2 10.43"
+.TH PCRE2GREP 1 "20 November 2023" "PCRE2 10.43"
 .SH NAME
 pcre2grep - a grep with Perl-compatible regular expressions.
 .SH SYNOPSIS
@@ -367,6 +367,10 @@ mode, \fB--colour\fP has no effect, and no context is shown. That is, the
 match in a line, each of them is shown separately. This option is mutually
 exclusive with \fB--output\fP, \fB--line-offsets\fP, and \fB--only-matching\fP.
 .TP
+\fB--group-separator\fP=\fItext\fP
+Output this text string instead of two hyphens between groups of lines when
+\fB-A\fP, \fB-B\fP, or \fB-C\fP is in use. See also \fB--no-group-separator\fP.
+.TP
 \fB-H\fP, \fB--with-filename\fP
 Force the inclusion of the file name at the start of output lines when
 searching a single file. The file name is not normally shown in this case.
@@ -590,6 +594,11 @@ being output, it precedes the line number. When the \fB-M\fP option causes a
 pattern to match more than one line, only the first is preceded by its line
 number. This option is forced if \fB--line-offsets\fP is used.
 .TP
+\fB--no-group-separator\fP\fP
+Do not output a separator between groups of lines when \fB-A\fP, \fB-B\fP, or
+\fB-C\fP is in use. The default is to output a line containing two hyphens. See
+also \fB--group-separator\fP.
+.TP
 \fB--no-jit\fP
 If the PCRE2 library is built with support for just-in-time compiling (which
 speeds up matching), \fBpcre2grep\fP automatically makes use of this, unless it
@@ -997,6 +1006,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 08 February 2023
+Last updated: 20 November 2023
 Copyright (c) 1997-2023 University of Cambridge.
 .fi

src/pcre2grep.c

@@ -211,6 +211,7 @@ static const char *dee_option = NULL;
 static const char *DEE_option = NULL;
 static const char *locale = NULL;
 static const char *newline_arg = NULL;
+static const char *group_separator = "--";
 static const char *om_separator = NULL;
 static const char *stdin_name = "(standard input)";
 static const char *output_text = NULL;
@@ -425,6 +426,8 @@ used to identify them. */
 #define N_OM_CAPTURE   (-24)
 #define N_ALLABSK      (-25)
 #define N_POSIX_DIGIT  (-26)
+#define N_GROUP_SEPARATOR (-27)
+#define N_NO_GROUP_SEPARATOR (-28)
 
 static option_item optionlist[] = {
   { OP_NODATA,     N_NULL,   NULL,              "",              "terminate options" },
@@ -448,6 +451,7 @@ static option_item optionlist[] = {
   { OP_FILELIST,   'f',      &pattern_files_data, "file=path",   "read patterns from file" },
   { OP_FILELIST,   N_FILE_LIST, &file_lists_data, "file-list=path","read files to search from file" },
   { OP_NODATA,     N_FOFFSETS, NULL,            "file-offsets",  "output file offsets, not text" },
+  { OP_STRING,     N_GROUP_SEPARATOR, &group_separator, "group-separator=text", "set separator between groups of lines" },
   { OP_NODATA,     'H',      NULL,              "with-filename", "force the prefixing filename on output" },
   { OP_NODATA,     'h',      NULL,              "no-filename",   "suppress the prefixing filename on output" },
   { OP_NODATA,     'I',      NULL,              "",              "treat binary files as not matching (ignore)" },
@@ -471,6 +475,7 @@ static option_item optionlist[] = {
 #else
   { OP_NODATA,     N_NOJIT,  NULL,              "no-jit",        "ignored: this pcre2grep does not support JIT" },
 #endif
+  { OP_NODATA,     N_NO_GROUP_SEPARATOR, NULL,   "no-group-separator", "suppress separators between groups of lines" },
   { OP_STRING,     'O',      &output_text,       "output=text",   "show only this text (possibly expanded)" },
   { OP_OP_NUMBERS, 'o',      &only_matching_data, "only-matching=n", "show only the part of the line that matched" },
   { OP_STRING,     N_OM_SEPARATOR, &om_separator, "om-separator=text", "set separator for multiple -o output" },
@@ -2954,7 +2959,8 @@ while (ptr < endptr)
 
       if (hyphenpending)
         {
-        fprintf(stdout, "--" STDOUT_NL);
+        if (group_separator != NULL)
+          fprintf(stdout, "%s%s", group_separator, STDOUT_NL);
         hyphenpending = FALSE;
         hyphenprinted = TRUE;
         }
@@ -2975,8 +2981,9 @@ while (ptr < endptr)
           p = previous_line(p, main_buffer);
           }
 
-        if (lastmatchnumber > 0 && p > lastmatchrestart && !hyphenprinted)
-          fprintf(stdout, "--" STDOUT_NL);
+        if (lastmatchnumber > 0 && p > lastmatchrestart && !hyphenprinted &&
+            group_separator != NULL)
+          fprintf(stdout, "%s%s", group_separator, STDOUT_NL);
 
         while (p < ptr)
           {
@@ -3590,6 +3597,7 @@ switch(letter)
   case N_LOFFSETS: line_offsets = number = TRUE; break;
   case N_NOJIT: use_jit = FALSE; break;
   case N_ALLABSK: extra_options |= PCRE2_EXTRA_ALLOW_LOOKAROUND_BSK; break;
+  case N_NO_GROUP_SEPARATOR: group_separator = NULL; break;
   case 'a': binary_files = BIN_TEXT; break;
   case 'c': count_only = TRUE; break;
   case N_POSIX_DIGIT: posix_digit = TRUE; break;

testdata/grepoutput

@@ -1232,3 +1232,24 @@ RC=2
 The word is cat in this line
 The caterpillar sat on the mat
 The snowcat is not an animal
+---------------------------- Test 152 -----------------------------
+24:four
+25-five
+26-six
+27-seven
+++
+34:fourteen
+35-fifteen
+36-sixteen
+37-seventeen
+RC=0
+---------------------------- Test 153 -----------------------------
+24:four
+25-five
+26-six
+27-seven
+34:fourteen
+35-fifteen
+36-sixteen
+37-seventeen
+RC=0