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Make it clearer what display_word_wrap() does and set the margins more appropriately when the terminal size is small.

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This commit is contained in:
Andrew Wood
2026-04-07 23:08:53 +01:00
parent 52585447f0
commit 0eab393715
1 changed files with 31 additions and 18 deletions
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src/main/help.c
+31 -18
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@@ -50,7 +50,8 @@ static size_t display_width(const char *string)
* The 7-bit ASCII version of display_word_wrap() below - does not
* understand multi-byte characters.
*/
static void display_word_wrap_7bit(const char *string, size_t display_width, size_t left_margin)
static void display_word_wrap_7bit(const char *string, size_t display_width, size_t first_line_start,
size_t left_margin)
{
const char *start;
const char *end;
@@ -61,6 +62,8 @@ static void display_word_wrap_7bit(const char *string, size_t display_width, siz
start = string;
wrap_at_width = display_width;
if (wrap_at_width > first_line_start)
wrap_at_width -= first_line_start;
/* Wrap lines that are too long. */
while (strlen(start) > wrap_at_width) { /* flawfinder: ignore */
@@ -106,13 +109,15 @@ static void display_word_wrap_7bit(const char *string, size_t display_width, siz
/*
* Output a null-terminated string to standard output, word wrapping to
* "display_width" display character positions, and left-padding any new
* lines after the first one with "left_margin" spaces.
* "display_width" display character positions, assuming that the first line
* starts with the cursor already at "first_line_start" display character
* positions from the left, and left-padding any new lines after the first
* one with "left_margin" spaces.
*
* Wide characters are handled if NLS is enabled, but if they can't be, this
* falls back to a version which just counts bytes as characters.
*/
static void display_word_wrap(const char *string, size_t display_width, size_t left_margin)
static void display_word_wrap(const char *string, size_t display_width, size_t first_line_start, size_t left_margin)
{
#if defined(ENABLE_NLS) && defined(HAVE_WCHAR_H)
size_t wrap_at_width;
@@ -121,6 +126,9 @@ static void display_word_wrap(const char *string, size_t display_width, size_t l
wchar_t *wide_string;
size_t start_idx, end_idx, chars_remaining;
debug("[%s], display_width=%d, first_line_start=%d, left_margin=%d", string, (int) display_width,
(int) first_line_start, (int) left_margin);
if (NULL == string)
return;
@@ -132,7 +140,7 @@ static void display_word_wrap(const char *string, size_t display_width, size_t l
/*@+nullpass@ */
if (wide_char_count == (size_t) -1) {
debug("%s: %s: %s", "mbstowcs", string, strerror(errno));
display_word_wrap_7bit(string, display_width, left_margin);
display_word_wrap_7bit(string, display_width, first_line_start, left_margin);
return;
}
@@ -145,7 +153,7 @@ static void display_word_wrap(const char *string, size_t display_width, size_t l
wide_string = malloc(wide_string_buffer_size);
if (NULL == wide_string) {
perror("malloc");
display_word_wrap_7bit(string, display_width, left_margin);
display_word_wrap_7bit(string, display_width, first_line_start, left_margin);
return;
}
memset(wide_string, 0, wide_string_buffer_size);
@@ -155,12 +163,14 @@ static void display_word_wrap(const char *string, size_t display_width, size_t l
if (mbstowcs(wide_string, string, 1 + wide_char_count) == (size_t) -1) {
debug("%s: %s: %s", "mbstowcs", string, strerror(errno));
free(wide_string);
display_word_wrap_7bit(string, display_width, left_margin);
display_word_wrap_7bit(string, display_width, first_line_start, left_margin);
return;
}
start_idx = 0;
wrap_at_width = display_width;
if (wrap_at_width > first_line_start)
wrap_at_width -= first_line_start;
chars_remaining = wide_char_count;
/* Wrap lines that are too long. */
@@ -240,7 +250,7 @@ static void display_word_wrap(const char *string, size_t display_width, size_t l
free(wide_string);
#else /* ! defined(ENABLE_NLS) && defined(HAVE_WCHAR_H) */
display_word_wrap_7bit(string, display_width, left_margin);
display_word_wrap_7bit(string, display_width, first_line_start, left_margin);
#endif /* defined(ENABLE_NLS) && defined(HAVE_WCHAR_H) */
}
@@ -481,7 +491,7 @@ void display_help(void)
*/
program_description = _("Concatenate FILE(s), or standard input, to standard output, with monitoring.");
if (NULL != program_description) {
display_word_wrap(program_description, right_margin, 0);
display_word_wrap(program_description, right_margin, 0, 0);
printf("\n");
}
@@ -554,9 +564,12 @@ void display_help(void)
* Set the left margin for the option descriptions, based on the
* widest option width, or (right margin - min_description_width),
* whichever is less, so that there is always room for
* "min_description_width" characters of description.
* "min_description_width" characters of description. If there's
* not even room for that, set the left margin to 2.
*/
description_left_margin = right_margin - min_description_width;
description_left_margin = 2;
if (right_margin > (min_description_width + 2))
description_left_margin = right_margin - min_description_width;
if (widest_option_width < description_left_margin) {
description_left_margin = widest_option_width;
}
@@ -597,18 +610,18 @@ void display_help(void)
}
/*
* If the option is too wide, start a new line for the
* description. In both cases, pad with spaces up to the
* description left margin.
* If the option (with 2 trailing spaces) is too wide, start
* a new line for the description. In both cases, pad with
* spaces up to the description left margin.
*/
if (option_width > description_left_margin) {
if ((option_width + 2) > description_left_margin) {
printf("\n%*s", (int) description_left_margin, "");
} else if (option_width < description_left_margin) {
printf("%*s", (int) (description_left_margin - option_width), "");
}
/* Output the description, word wrapped. */
display_word_wrap(definition->opt_description, right_margin - description_left_margin,
display_word_wrap(definition->opt_description, right_margin, description_left_margin,
description_left_margin);
printf("\n");
@@ -620,11 +633,11 @@ void display_help(void)
format_sequence_header = _("Supported format sequences:");
if (NULL != format_sequence_header) {
printf("\n");
display_word_wrap(format_sequence_header, right_margin, 0);
display_word_wrap(format_sequence_header, right_margin, 0, 0);
printf("\n");
}
printf("\n ");
display_word_wrap(format_sequences, right_margin, 2);
display_word_wrap(format_sequences, right_margin, 2, 2);
free(format_sequences);
printf("\n");
}