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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-08-15 20:42:52 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2007-08-15 20:42:52 +0000
commit033e592cbc96c150c67ac9be7df65e314be5c8f8 (patch)
tree0ec512a6215295775b28eb49a4150fadf101465e
parentab9c44b1a41c9a17cd0f8a8f1e5517756ccb8bf0 (diff)
downloadbusybox-033e592cbc96c150c67ac9be7df65e314be5c8f8.tar.gz
busybox-033e592cbc96c150c67ac9be7df65e314be5c8f8.tar.bz2
more: by Tristan Schmelcher <tpkschme@engmail.uwaterloo.ca>:
- Fixed a number of deficiencies in the line wrapping. - Fixed a bug where the page could scroll multiple times per keypress. - Re-read terminal dimensions after user input, in case they resized the terminal while we were waiting. - Added an 'R' key to print the rest of the file without prompting. - Crudely support tabs in the line-wrapping code by converting them to 8 spaces.
-rw-r--r--util-linux/more.c108
1 files changed, 62 insertions, 46 deletions
diff --git a/util-linux/more.c b/util-linux/more.c
index 4083d8eea..92ebdfea9 100644
--- a/util-linux/more.c
+++ b/util-linux/more.c
@@ -29,11 +29,11 @@ struct globals {
};
#define G (*(struct globals*)bb_common_bufsiz1)
//#define G (*ptr_to_globals)
+#define INIT_G() ((void)0)
+//#define INIT_G() PTR_TO_GLOBALS = xzalloc(sizeof(G))
#define initial_settings (G.initial_settings)
#define new_settings (G.new_settings )
#define cin_fileno (G.cin_fileno )
-#define INIT_G() ((void)0)
-//#define INIT_G() PTR_TO_GLOBALS = xzalloc(sizeof(G))
#define setTermSettings(fd, argp) tcsetattr(fd, TCSANOW, argp)
#define getTermSettings(fd, argp) tcgetattr(fd, argp)
@@ -50,16 +50,20 @@ static void gotsig(int sig)
#define setTermSettings(fd, argp) ((void)0)
#endif /* FEATURE_USE_TERMIOS */
+#define CONVERTED_TAB_SIZE 8
int more_main(int argc, char **argv);
int more_main(int argc, char **argv)
{
- int c, lines, input = 0;
- int please_display_more_prompt = 0;
+ int c = c; /* for gcc */
+ int lines;
+ int input = 0;
+ int spaces = 0;
+ int please_display_more_prompt;
struct stat st;
FILE *file;
FILE *cin;
- int len, page_height;
+ int len;
int terminal_width;
int terminal_height;
@@ -87,7 +91,6 @@ int more_main(int argc, char **argv)
signal(SIGQUIT, gotsig);
signal(SIGTERM, gotsig);
#endif
- please_display_more_prompt = 2;
do {
file = stdin;
@@ -99,19 +102,21 @@ int more_main(int argc, char **argv)
st.st_size = 0;
fstat(fileno(file), &st);
- please_display_more_prompt &= ~1;
+ please_display_more_prompt = 0;
/* never returns w, h <= 1 */
get_terminal_width_height(fileno(cin), &terminal_width, &terminal_height);
- terminal_width -= 1;
terminal_height -= 1;
len = 0;
lines = 0;
- page_height = terminal_height;
- while ((c = getc(file)) != EOF) {
- if ((please_display_more_prompt & 3) == 3) {
+ while (spaces || (c = getc(file)) != EOF) {
+ int wrap;
+ if (spaces)
+ spaces--;
+ loop_top:
+ if (input != 'r' && please_display_more_prompt) {
len = printf("--More-- ");
- if (/*file != stdin &&*/ st.st_size > 0) {
+ if (st.st_size > 0) {
len += printf("(%d%% of %"OFF_FMT"d bytes)",
(int) (ftello(file)*100 / st.st_size),
st.st_size);
@@ -122,23 +127,44 @@ int more_main(int argc, char **argv)
* We've just displayed the "--More--" prompt, so now we need
* to get input from the user.
*/
- input = getc(cin);
+ for (;;) {
+ input = getc(cin);
+ input = tolower(input);
#if !ENABLE_FEATURE_USE_TERMIOS
- printf("\033[A"); /* up cursor */
+ printf("\033[A"); /* up cursor */
#endif
- /* Erase the "More" message */
- printf("\r%*s\r", len, "");
+ /* Erase the last message */
+ printf("\r%*s\r", len, "");
+
+ /* Due to various multibyte escape
+ * sequences, it's not ok to accept
+ * any input as a command to scroll
+ * the screen. We only allow known
+ * commands, else we show help msg. */
+ if (input == ' ' || input == '\n' || input == 'q' || input == 'r')
+ break;
+ len = printf("(Enter:next line Space:next page Q:quit R:show the rest)");
+ }
len = 0;
lines = 0;
- /* Bottom line on page will become top line
- * after one page forward. Thus -1: */
- page_height = terminal_height - 1;
- please_display_more_prompt &= ~1;
+ please_display_more_prompt = 0;
if (input == 'q')
goto end;
+
+ /* The user may have resized the terminal.
+ * Re-read the dimensions. */
+ get_terminal_width_height(cin_fileno, &terminal_width, &terminal_height);
+ terminal_height -= 1;
}
+ /* Crudely convert tabs into spaces, which are
+ * a bajillion times easier to deal with. */
+ if (c == '\t') {
+ spaces = CONVERTED_TAB_SIZE - 1;
+ c = ' ';
+ }
+
/*
* There are two input streams to worry about here:
*
@@ -149,34 +175,24 @@ int more_main(int argc, char **argv)
* see if any characters have been hit in the _input_ stream. This
* allows the user to quit while in the middle of a file.
*/
- if (c == '\n') {
- /* increment by just one line if we are at
- * the end of this line */
- if (input == '\n')
- please_display_more_prompt |= 1;
- /* Adjust the terminal height for any overlap, so that
- * no lines get lost off the top. */
- if (len >= terminal_width) {
- int quot, rem;
- quot = len / terminal_width;
- rem = len - (quot * terminal_width);
- page_height -= (quot - 1);
- if (rem)
- page_height--;
- }
- if (++lines >= page_height) {
- please_display_more_prompt |= 1;
- }
+ wrap = (++len > terminal_width);
+ if (c == '\n' || wrap) {
+ /* Then outputting this character
+ * will move us to a new line. */
+ if (++lines >= terminal_height || input == '\n')
+ please_display_more_prompt = 1;
len = 0;
}
- /*
- * If we just read a newline from the file being 'mored' and any
- * key other than a return is hit, scroll by one page
- */
- putc(c, stdout);
- /* My small mind cannot fathom tabs, backspaces,
- * and UTF-8 */
- len++;
+ if (c != '\n' && wrap) {
+ /* Then outputting this will also put a character on
+ * the beginning of that new line. Thus we first want to
+ * display the prompt (if any), so we skip the putchar()
+ * and go back to the top of the loop, without reading
+ * a new character. */
+ goto loop_top;
+ }
+ /* My small mind cannot fathom backspaces and UTF-8 */
+ putchar(c);
}
fclose(file);
fflush(stdout);