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terminal-util: Move various functions to ansi-color.c

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This commit is contained in:
Daan De Meyer
2025-05-09 11:33:33 +02:00
parent c992250c24
commit 7227d5bfff
6 changed files with 130 additions and 106 deletions
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src/basic/ansi-color.c
+98
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@@ -0,0 +1,98 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "ansi-color.h"
#include "log.h"
#include "process-util.h"
#include "string-table.h"
#include "strv.h"
#include "terminal-util.h"
static volatile int cached_color_mode = _COLOR_MODE_INVALID;
static volatile int cached_underline_enabled = -1;
bool underline_enabled(void) {
if (cached_underline_enabled < 0) {
/* The Linux console doesn't support underlining, turn it off, but only there. */
if (colors_enabled())
cached_underline_enabled = !streq_ptr(getenv("TERM"), "linux");
else
cached_underline_enabled = false;
}
return cached_underline_enabled;
}
void reset_ansi_feature_caches(void) {
cached_color_mode = _COLOR_MODE_INVALID;
cached_underline_enabled = -1;
}
ColorMode parse_systemd_colors(void) {
const char *e;
e = getenv("SYSTEMD_COLORS");
if (!e)
return _COLOR_MODE_INVALID;
ColorMode m = color_mode_from_string(e);
if (m < 0)
return log_debug_errno(m, "Failed to parse $SYSTEMD_COLORS value '%s', ignoring: %m", e);
return m;
}
static ColorMode get_color_mode_impl(void) {
/* Returns the mode used to choose output colors. The possible modes are COLOR_OFF for no colors,
* COLOR_16 for only the base 16 ANSI colors, COLOR_256 for more colors, and COLOR_24BIT for
* unrestricted color output. */
/* First, we check $SYSTEMD_COLORS, which is the explicit way to change the mode. */
ColorMode m = parse_systemd_colors();
if (m >= 0)
return m;
/* Next, check for the presence of $NO_COLOR; value is ignored. */
if (getenv("NO_COLOR"))
return COLOR_OFF;
/* If the above didn't work, we turn colors off unless we are on a TTY. And if we are on a TTY we
* turn it off if $TERM is set to "dumb". There's one special tweak though: if we are PID 1 then we
* do not check whether we are connected to a TTY, because we don't keep /dev/console open
* continuously due to fear of SAK, and hence things are a bit weird. */
if (getpid_cached() == 1 ? getenv_terminal_is_dumb() : terminal_is_dumb())
return COLOR_OFF;
/* We failed to figure out any reason to *disable* colors. Let's see how many colors we shall use. */
if (STRPTR_IN_SET(getenv("COLORTERM"),
"truecolor",
"24bit"))
return COLOR_24BIT;
/* Note that the Linux console can only display 16 colors. We still enable 256 color mode
* even for PID1 output though (which typically goes to the Linux console), since the Linux
* console is able to parse the 256 color sequences and automatically map them to the closest
* color in the 16 color palette (since kernel 3.16). Doing 256 colors is nice for people who
* invoke systemd in a container or via a serial link or such, and use a true 256 color
* terminal to do so. */
return COLOR_256;
}
ColorMode get_color_mode(void) {
if (cached_color_mode < 0)
cached_color_mode = get_color_mode_impl();
return cached_color_mode;
}
static const char* const color_mode_table[_COLOR_MODE_MAX] = {
[COLOR_OFF] = "off",
[COLOR_16] = "16",
[COLOR_256] = "256",
[COLOR_24BIT] = "24bit",
};
DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(color_mode, ColorMode, COLOR_24BIT);
src/basic/ansi-color.h
+28 -1
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@@ -1,7 +1,34 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once
#include "terminal-util.h"
#include <errno.h>
#include "macro.h"
/* Limits the use of ANSI colors to a subset. */
typedef enum ColorMode {
COLOR_OFF, /* No colors, monochrome output. */
COLOR_16, /* Only the base 16 colors. */
COLOR_256, /* Only 256 colors. */
COLOR_24BIT, /* For truecolor or 24bit color support, no restriction. */
_COLOR_MODE_MAX,
_COLOR_MODE_INVALID = -EINVAL,
} ColorMode;
const char* color_mode_to_string(ColorMode m) _const_;
ColorMode color_mode_from_string(const char *s) _pure_;
ColorMode get_color_mode(void);
static inline bool colors_enabled(void) {
/* Returns true if colors are considered supported on our stdout. */
return get_color_mode() != COLOR_OFF;
}
ColorMode parse_systemd_colors(void);
bool underline_enabled(void);
void reset_ansi_feature_caches(void);
/* Regular colors */
#define ANSI_BLACK "\x1B[0;30m" /* Some type of grey usually. */
src/basic/meson.build
+1
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@@ -4,6 +4,7 @@ basic_sources = files(
'MurmurHash2.c',
'af-list.c',
'alloc-util.c',
'ansi-color.c',
'architecture.c',
'argv-util.c',
'arphrd-util.c',
src/basic/terminal-util.c
+2 -85
View File
@@ -60,8 +60,6 @@ static volatile unsigned cached_lines = 0;
static volatile int cached_on_tty = -1;
static volatile int cached_on_dev_null = -1;
static volatile int cached_color_mode = _COLOR_MODE_INVALID;
static volatile int cached_underline_enabled = -1;
bool isatty_safe(int fd) {
assert(fd >= 0);
@@ -1433,10 +1431,10 @@ void reset_terminal_feature_caches(void) {
cached_columns = 0;
cached_lines = 0;
cached_color_mode = _COLOR_MODE_INVALID;
cached_underline_enabled = -1;
cached_on_tty = -1;
cached_on_dev_null = -1;
reset_ansi_feature_caches();
}
bool on_tty(void) {
@@ -1753,72 +1751,6 @@ bool terminal_is_dumb(void) {
return getenv_terminal_is_dumb();
}
static const char* const color_mode_table[_COLOR_MODE_MAX] = {
[COLOR_OFF] = "off",
[COLOR_16] = "16",
[COLOR_256] = "256",
[COLOR_24BIT] = "24bit",
};
DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(color_mode, ColorMode, COLOR_24BIT);
static ColorMode parse_systemd_colors(void) {
const char *e;
e = getenv("SYSTEMD_COLORS");
if (!e)
return _COLOR_MODE_INVALID;
ColorMode m = color_mode_from_string(e);
if (m < 0)
return log_debug_errno(m, "Failed to parse $SYSTEMD_COLORS value '%s', ignoring: %m", e);
return m;
}
static ColorMode get_color_mode_impl(void) {
/* Returns the mode used to choose output colors. The possible modes are COLOR_OFF for no colors,
* COLOR_16 for only the base 16 ANSI colors, COLOR_256 for more colors, and COLOR_24BIT for
* unrestricted color output. */
/* First, we check $SYSTEMD_COLORS, which is the explicit way to change the mode. */
ColorMode m = parse_systemd_colors();
if (m >= 0)
return m;
/* Next, check for the presence of $NO_COLOR; value is ignored. */
if (getenv("NO_COLOR"))
return COLOR_OFF;
/* If the above didn't work, we turn colors off unless we are on a TTY. And if we are on a TTY we
* turn it off if $TERM is set to "dumb". There's one special tweak though: if we are PID 1 then we
* do not check whether we are connected to a TTY, because we don't keep /dev/console open
* continuously due to fear of SAK, and hence things are a bit weird. */
if (getpid_cached() == 1 ? getenv_terminal_is_dumb() : terminal_is_dumb())
return COLOR_OFF;
/* We failed to figure out any reason to *disable* colors. Let's see how many colors we shall use. */
if (STRPTR_IN_SET(getenv("COLORTERM"),
"truecolor",
"24bit"))
return COLOR_24BIT;
/* Note that the Linux console can only display 16 colors. We still enable 256 color mode
* even for PID1 output though (which typically goes to the Linux console), since the Linux
* console is able to parse the 256 color sequences and automatically map them to the closest
* color in the 16 color palette (since kernel 3.16). Doing 256 colors is nice for people who
* invoke systemd in a container or via a serial link or such, and use a true 256 color
* terminal to do so. */
return COLOR_256;
}
ColorMode get_color_mode(void) {
if (cached_color_mode < 0)
cached_color_mode = get_color_mode_impl();
return cached_color_mode;
}
bool dev_console_colors_enabled(void) {
_cleanup_free_ char *s = NULL;
ColorMode m;
@@ -1843,21 +1775,6 @@ bool dev_console_colors_enabled(void) {
return !streq_ptr(s, "dumb");
}
bool underline_enabled(void) {
if (cached_underline_enabled < 0) {
/* The Linux console doesn't support underlining, turn it off, but only there. */
if (colors_enabled())
cached_underline_enabled = !streq_ptr(getenv("TERM"), "linux");
else
cached_underline_enabled = false;
}
return cached_underline_enabled;
}
int vt_restore(int fd) {
static const struct vt_mode mode = {
src/basic/terminal-util.h
-20
View File
@@ -129,26 +129,6 @@ bool on_tty(void);
bool getenv_terminal_is_dumb(void);
bool terminal_is_dumb(void);
/* Limits the use of ANSI colors to a subset. */
typedef enum ColorMode {
COLOR_OFF, /* No colors, monochrome output. */
COLOR_16, /* Only the base 16 colors. */
COLOR_256, /* Only 256 colors. */
COLOR_24BIT, /* For truecolor or 24bit color support, no restriction. */
_COLOR_MODE_MAX,
_COLOR_MODE_INVALID = -EINVAL,
} ColorMode;
const char* color_mode_to_string(ColorMode m) _const_;
ColorMode color_mode_from_string(const char *s) _pure_;
ColorMode get_color_mode(void);
static inline bool colors_enabled(void) {
/* Returns true if colors are considered supported on our stdout. */
return get_color_mode() != COLOR_OFF;
}
bool underline_enabled(void);
bool dev_console_colors_enabled(void);
int get_ctty_devnr(pid_t pid, dev_t *ret);