[PATCH] color.h: document and modernize header

From

Stefan Beller <sbeller@google.com>

Date

Feb 8, 2018, 20:15 UTC

Message-ID

<20180208201546.194935-1-sbeller@google.com>

Signed-off-by: Stefan Beller <sbeller@google.com>
---

 This used to be part of  sb/blame-color, but I realized this is
 not strictly needed for that series, so I am sending it out alone.
 
 I would think I have addressed all concerns raised in 
 https://public-inbox.org/git/xmqqr2r088p3.fsf@gitster.mtv.corp.google.com/
 specifically the NEEDSWORK was dropped and this one function was just
 put into grep.c
 
 Thanks,
 Stefan

 color.c |  7 -------
 color.h | 52 ++++++++++++++++++++++++++++++++++++++--------------
 grep.c  |  5 +++++
 3 files changed, 43 insertions(+), 21 deletions(-)

diff --git a/color.c b/color.c
index d48dd947c9..f277e72e4c 100644
--- a/color.c
+++ b/color.c
@@ -161,11 +161,6 @@ int color_parse(const char *value, char *dst)
 	return color_parse_mem(value, strlen(value), dst);
 }
 
-void color_set(char *dst, const char *color_bytes)
-{
-	xsnprintf(dst, COLOR_MAXLEN, "%s", color_bytes);
-}
-
 /*
  * Write the ANSI color codes for "c" to "out"; the string should
  * already have the ANSI escape code in it. "out" should have enough
@@ -399,8 +394,6 @@ static int color_vfprintf(FILE *fp, const char *color, const char *fmt,
 	return r;
 }
 
-
-
 int color_fprintf(FILE *fp, const char *color, const char *fmt, ...)
 {
 	va_list args;
diff --git a/color.h b/color.h
index fd2b688dfb..8c7e6c41c2 100644
--- a/color.h
+++ b/color.h
@@ -72,26 +72,50 @@ extern int color_stdout_is_tty;
  * Use the first one if you need only color config; the second is a convenience
  * if you are just going to change to git_default_config, too.
  */
-int git_color_config(const char *var, const char *value, void *cb);
-int git_color_default_config(const char *var, const char *value, void *cb);
+extern int git_color_config(const char *var, const char *value, void *cb);
+extern int git_color_default_config(const char *var, const char *value, void *cb);
 
 /*
- * Set the color buffer (which must be COLOR_MAXLEN bytes)
- * to the raw color bytes; this is useful for initializing
- * default color variables.
+ * Parse a config option, which can be a boolean or one of
+ * "never", "auto", "always". Return a constant of
+ * GIT_COLOR_NEVER for "never" or negative boolean,
+ * GIT_COLOR_ALWAYS for "always" or a positive boolean,
+ * and GIT_COLOR_AUTO for "auto".
  */
-void color_set(char *dst, const char *color_bytes);
+extern int git_config_colorbool(const char *var, const char *value);
 
-int git_config_colorbool(const char *var, const char *value);
-int want_color(int var);
-int color_parse(const char *value, char *dst);
-int color_parse_mem(const char *value, int len, char *dst);
+/*
+ * Resolve the constants as returned by git_config_colorbool()
+ * (specifically "auto") to a boolean answer.
+ */
+extern int want_color(int var);
+
+/*
+ * Translate a Git color from 'value' into a string that the terminal can
+ * interpret and store it into 'dst'. The Git color values are of the form
+ * "foreground [background] [attr]" where fore- and background can be a color
+ * name ("red"), a RGB code (#0xFF0000) or a 256-color-mode from the terminal.
+ */
+extern int color_parse(const char *value, char *dst);
+extern int color_parse_mem(const char *value, int len, char *dst);
+
+/*
+ * Output the formatted string in the specified color (and then reset to normal
+ * color so subsequent output is uncolored). Omits the color encapsulation if
+ * `color` is NULL. The `color_fprintf_ln` prints a new line after resetting
+ * the color. The `color_print_strbuf` prints the given pre-formatted strbuf
+ * instead, up to its first NUL character.
+ */
 __attribute__((format (printf, 3, 4)))
-int color_fprintf(FILE *fp, const char *color, const char *fmt, ...);
+extern int color_fprintf(FILE *fp, const char *color, const char *fmt, ...);
 __attribute__((format (printf, 3, 4)))
-int color_fprintf_ln(FILE *fp, const char *color, const char *fmt, ...);
-void color_print_strbuf(FILE *fp, const char *color, const struct strbuf *sb);
+extern int color_fprintf_ln(FILE *fp, const char *color, const char *fmt, ...);
+extern void color_print_strbuf(FILE *fp, const char *color, const struct strbuf *sb);
 
-int color_is_nil(const char *color);
+/*
+ * Check if the given color is GIT_COLOR_NIL that means "no color selected".
+ * The caller needs to replace the color with the actual desired color.
+ */
+extern int color_is_nil(const char *color);
 
 #endif /* COLOR_H */
diff --git a/grep.c b/grep.c
index 3d7cd0e96f..834b8eb439 100644
--- a/grep.c
+++ b/grep.c
@@ -18,6 +18,11 @@ static void std_output(struct grep_opt *opt, const void *buf, size_t size)
 	fwrite(buf, size, 1, stdout);
 }
 
+static void color_set(char *dst, const char *color_bytes)
+{
+	xsnprintf(dst, COLOR_MAXLEN, "%s", color_bytes);
+}
+
 /*
  * Initialize the grep_defaults template with hardcoded defaults.
  * We could let the compiler do this, but without C99 initializers

-- 
2.15.1.433.g936d1b9894.dirty