[PATCH v3 4/7] grep.c: display column number of first match

[Taylor Blau]

To prepare for 'git grep' learning '--column-number', teach grep.c's
show_line() how to show the column of the first match on non-context
line.

Signed-off-by: Taylor Blau <m...@ttaylorr.com>
---
 grep.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/grep.c b/grep.c
index fb0fa23231..d58d940afb 100644
--- a/grep.c
+++ b/grep.c
@@ -1364,7 +1364,7 @@ static int next_match(struct grep_opt *opt, char *bol, 
char *eol,
 }
 
 static void show_line(struct grep_opt *opt, char *bol, char *eol,
-                     const char *name, unsigned lno, char sign)
+                     const char *name, unsigned lno, unsigned cno, char sign)
 {
        int rest = eol - bol;
        const char *match_color, *line_color = NULL;
@@ -1399,6 +1399,17 @@ static void show_line(struct grep_opt *opt, char *bol, 
char *eol,
                output_color(opt, buf, strlen(buf), opt->color_lineno);
                output_sep(opt, sign);
        }
+       /**
+        * Treat 'cno' as the 1-indexed offset from the start of a non-context
+        * line to its first match. Otherwise, 'cno' is 0 indicating that we are
+        * being called with a context line.
+        */
+       if (opt->columnnum && cno) {
+               char buf[32];
+               xsnprintf(buf, sizeof(buf), "%d", cno);
+               output_color(opt, buf, strlen(buf), opt->color_columnno);
+               output_sep(opt, sign);
+       }
        if (opt->color) {
                regmatch_t match;
                enum grep_context ctx = GREP_CONTEXT_BODY;
@@ -1504,7 +1515,7 @@ static void show_funcname_line(struct grep_opt *opt, 
struct grep_source *gs,
                        break;
 
                if (match_funcname(opt, gs, bol, eol)) {
-                       show_line(opt, bol, eol, gs->name, lno, '=');
+                       show_line(opt, bol, eol, gs->name, lno, 0, '=');
                        break;
                }
        }
@@ -1569,7 +1580,7 @@ static void show_pre_context(struct grep_opt *opt, struct 
grep_source *gs,
 
                while (*eol != '\n')
                        eol++;
-               show_line(opt, bol, eol, gs->name, cur, sign);
+               show_line(opt, bol, eol, gs->name, cur, 0, sign);
                bol = eol + 1;
                cur++;
        }
@@ -1833,7 +1844,7 @@ static int grep_source_1(struct grep_opt *opt, struct 
grep_source *gs, int colle
                                show_pre_context(opt, gs, bol, eol, lno);
                        else if (opt->funcname)
                                show_funcname_line(opt, gs, bol, lno);
-                       show_line(opt, bol, eol, gs->name, lno, ':');
+                       show_line(opt, bol, eol, gs->name, lno, match.rm_so+1, 
':');
                        last_hit = lno;
                        if (opt->funcbody)
                                show_function = 1;
@@ -1862,7 +1873,7 @@ static int grep_source_1(struct grep_opt *opt, struct 
grep_source *gs, int colle
                        /* If the last hit is within the post context,
                         * we need to show this line.
                         */
-                       show_line(opt, bol, eol, gs->name, lno, '-');
+                       show_line(opt, bol, eol, gs->name, lno, match.rm_so+1, 
'-');
                }
 
        next_line:
-- 
2.17.0