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terminal-util: beef up show_menu()

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This modernizes the function a bit, and adds some bits:

1. whether to show numbers before entries is now optional, and if they
   are shown they are displayed in grey.

2. a common prefix can now be grayed out (later useful for completion
   support)

3. some variables have been named to clarify their purpose

4. the table display dimensions can now be auto-sized (by specifying
   SIZE_MAX and number of columns and column width)
This commit is contained in:
Lennart Poettering
2025-02-06 12:02:24 +01:00
parent 8fcd85768b
commit b6478aa12f
4 changed files with 90 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

78
src/basic/terminal-util.c
View File

@@ -281,38 +281,92 @@ bool any_key_to_proceed(void) {
return key != 'q';
}
int show_menu(char **x, unsigned n_columns, unsigned width, unsigned percentage) {
unsigned break_lines, break_modulo;
size_t n, per_column, i, j;
static size_t widest_list_element(char *const*l) {
size_t w = 0;
/* Returns the largest console width of all elements in 'l' */
STRV_FOREACH(i, l)
w = MAX(w, utf8_console_width(*i));
return w;
}
int show_menu(char **x,
size_t n_columns,
size_t column_width,
unsigned ellipsize_percentage,
const char *grey_prefix,
bool with_numbers) {
assert(n_columns > 0);
n = strv_length(x);
per_column = DIV_ROUND_UP(n, n_columns);
if (n_columns == SIZE_MAX)
n_columns = 3;
break_lines = lines();
if (column_width == SIZE_MAX) {
size_t widest = widest_list_element(x);
/* If not specified, derive column width from screen width */
size_t column_max = (columns()-1) / n_columns;
/* Subtract room for numbers */
if (with_numbers && column_max > 6)
column_max -= 6;
/* If columns would get too tight let's make this a linear list instead. */
if (column_max < 10 && widest > 10) {
n_columns = 1;
column_max = columns()-1;
if (with_numbers && column_max > 6)
column_max -= 6;
}
column_width = CLAMP(widest+1, 10U, column_max);
}
size_t n = strv_length(x);
size_t per_column = DIV_ROUND_UP(n, n_columns);
size_t break_lines = lines();
if (break_lines > 2)
break_lines--;
/* The first page gets two extra lines, since we want to show
* a title */
break_modulo = break_lines;
size_t break_modulo = break_lines;
if (break_modulo > 3)
break_modulo -= 3;
for (i = 0; i < per_column; i++) {
for (size_t i = 0; i < per_column; i++) {
for (j = 0; j < n_columns; j++) {
for (size_t j = 0; j < n_columns; j++) {
_cleanup_free_ char *e = NULL;
if (j * per_column + i >= n)
break;
e = ellipsize(x[j * per_column + i], width, percentage);
e = ellipsize(x[j * per_column + i], column_width, ellipsize_percentage);
if (!e)
return log_oom();
return -ENOMEM;
printf("%4zu) %-*s", j * per_column + i + 1, (int) width, e);
if (with_numbers)
printf("%s%4zu)%s ",
ansi_grey(),
j * per_column + i + 1,
ansi_normal());
if (grey_prefix && startswith(e, grey_prefix)) {
size_t k = MIN(strlen(grey_prefix), column_width);
printf("%s%.*s%s",
ansi_grey(),
(int) k, e,
ansi_normal());
printf("%-*s",
(int) (column_width - k), e+k);
} else
printf("%-*s", (int) column_width, e);
}
putchar('\n');

2
src/basic/terminal-util.h
View File

@@ -84,7 +84,7 @@ int read_one_char(FILE *f, char *ret, usec_t timeout, bool echo, bool *need_nl);
int ask_char(char *ret, const char *replies, const char *text, ...) _printf_(3, 4);
int ask_string(char **ret, const char *text, ...) _printf_(2, 3);
bool any_key_to_proceed(void);
int show_menu(char **x, unsigned n_columns, unsigned width, unsigned percentage);
int show_menu(char **x, size_t n_columns, size_t column_width, unsigned ellipsize_percentage, const char *grey_prefix, bool with_numbers);
int vt_disallocate(const char *name);

19
src/firstboot/firstboot.c
View File

@@ -135,7 +135,13 @@ static void print_welcome(int rfd) {
done = true;
}
static int prompt_loop(int rfd, const char *text, char **l, unsigned percentage, bool (*is_valid)(int rfd, const char *name), char **ret) {
static int prompt_loop(
int rfd,
const char *text,
char **l,
unsigned ellipsize_percentage,
bool (*is_valid)(int rfd, const char *name),
char **ret) {
int r;
assert(text);
@@ -144,7 +150,6 @@ static int prompt_loop(int rfd, const char *text, char **l, unsigned percentage,
for (;;) {
_cleanup_free_ char *p = NULL;
unsigned u;
r = ask_string(&p, strv_isempty(l) ? "%s %s (empty to skip): "
: "%s %s (empty to skip, \"list\" to list options): ",
@@ -159,14 +164,20 @@ static int prompt_loop(int rfd, const char *text, char **l, unsigned percentage,
if (!strv_isempty(l)) {
if (streq(p, "list")) {
r = show_menu(l, 3, 20, percentage);
r = show_menu(l,
/* n_columns= */ 3,
/* column_width= */ 20,
ellipsize_percentage,
/* grey_prefix= */ NULL,
/* with_numbers= */ true);
if (r < 0)
return r;
return log_error_errno(r, "Failed to show menu: %m");
putchar('\n');
continue;
}
unsigned u;
r = safe_atou(p, &u);
if (r >= 0) {
if (u <= 0 || u > strv_length(l)) {

11
src/home/homectl.c
View File

@@ -2530,7 +2530,6 @@ static int create_interactively(void) {
for (;;) {
_cleanup_free_ char *s = NULL;
unsigned u;
r = ask_string(&s,
"%s Please enter an auxiliary group for user %s (empty to continue, \"list\" to list available groups): ",
@@ -2552,15 +2551,21 @@ static int create_interactively(void) {
continue;
}
r = show_menu(available, /*n_columns=*/ 3, /*width=*/ 20, /*percentage=*/ 60);
r = show_menu(available,
/* n_columns= */ 3,
/* column_width= */ 20,
/* ellipsize_percentage= */ 60,
/* grey_prefix= */ NULL,
/* with_numbers= */ true);
if (r < 0)
return r;
return log_error_errno(r, "Failed to show menu: %m");
putchar('\n');
continue;
};
if (!strv_isempty(available)) {
unsigned u;
r = safe_atou(s, &u);
if (r >= 0) {
if (u <= 0 || u > strv_length(available)) {