Files
MontaukOS/programs/src/man/main.cpp
T

359 lines
9.5 KiB
C++

/*
* main.cpp
* Manual page viewer for MontaukOS
* Fullscreen pager with ANSI formatting and keyboard navigation
* Copyright (c) 2025 Daniel Hammer
*/
#include <montauk/syscall.h>
#include <montauk/heap.h>
#include <montauk/string.h>
using montauk::slen;
using montauk::starts_with;
using montauk::skip_spaces;
static void print_int(uint64_t n) {
if (n == 0) {
montauk::putchar('0');
return;
}
char buf[20];
int i = 0;
while (n > 0) {
buf[i++] = '0' + (n % 10);
n /= 10;
}
for (int j = i - 1; j >= 0; j--) {
montauk::putchar(buf[j]);
}
}
// ---- Pager rendering ----
static constexpr int MAN_MAX_LINES = 2048;
static int int_to_buf(char* buf, int n) {
if (n == 0) { buf[0] = '0'; return 1; }
char tmp[12];
int i = 0;
while (n > 0) { tmp[i++] = '0' + (n % 10); n /= 10; }
for (int j = 0; j < i; j++) buf[j] = tmp[i - 1 - j];
return i;
}
static void cursor_to(int row, int col) {
char seq[24] = "\033[";
int p = 2;
p += int_to_buf(seq + p, row);
seq[p++] = ';';
p += int_to_buf(seq + p, col);
seq[p++] = 'H';
seq[p] = '\0';
montauk::print(seq);
}
struct ManLine {
const char* text;
int len;
bool isSH;
bool isSS;
bool isBold;
bool isTH;
};
static void man_render(ManLine* lines, int totalLines, int scroll, int rows, int cols,
const char* name, int section) {
int contentRows = rows - 1;
for (int r = 0; r < contentRows; r++) {
cursor_to(r + 1, 1);
montauk::print("\033[2K");
int idx = scroll + r;
if (idx < 0 || idx >= totalLines) continue;
ManLine& ln = lines[idx];
if (ln.isTH) continue;
if (ln.isSH || ln.isSS || ln.isBold) {
montauk::print("\033[1m");
}
if (ln.isSS) {
montauk::print(" ");
}
int maxW = cols;
if (ln.isSS) maxW -= 3;
int printLen = ln.len;
if (printLen > maxW) printLen = maxW;
for (int c = 0; c < printLen; c++) {
montauk::putchar(ln.text[c]);
}
if (ln.isSH || ln.isSS || ln.isBold) {
montauk::print("\033[0m");
}
}
// Status bar
cursor_to(rows, 1);
montauk::print("\033[7m");
montauk::print(" Manual page ");
montauk::print(name);
montauk::putchar('(');
print_int((uint64_t)section);
montauk::putchar(')');
montauk::print(" line ");
print_int((uint64_t)(scroll + 1));
montauk::putchar('/');
print_int((uint64_t)totalLines);
int padCount = cols - 30 - slen(name);
for (int i = 0; i < padCount; i++) montauk::putchar(' ');
montauk::print("\033[0m");
}
// ---- Main ----
extern "C" void _start() {
// Get arguments passed by the shell (e.g. "intro" or "2 syscalls")
char argbuf[256];
montauk::getargs(argbuf, sizeof(argbuf));
const char* arg = skip_spaces(argbuf);
if (*arg == '\0') {
montauk::print("Usage: man <topic>\n");
montauk::print(" man <section> <topic>\n");
montauk::print("Try: man intro\n");
return;
}
// Parse optional section number and topic name
int section = 0;
const char* topic = arg;
if (arg[0] >= '1' && arg[0] <= '9' && arg[1] == ' ') {
section = arg[0] - '0';
topic = skip_spaces(arg + 2);
}
// Try to open man page file
int handle = -1;
int foundSection = 0;
char path[128];
if (section > 0) {
const char* prefix = "0:/man/";
int p = 0;
while (prefix[p]) { path[p] = prefix[p]; p++; }
int t = 0;
while (topic[t] && p < 120) { path[p++] = topic[t++]; }
path[p++] = '.';
path[p++] = '0' + section;
path[p] = '\0';
handle = montauk::open(path);
if (handle >= 0) foundSection = section;
} else {
for (int s = 1; s <= 9; s++) {
const char* prefix = "0:/man/";
int p = 0;
while (prefix[p]) { path[p] = prefix[p]; p++; }
int t = 0;
while (topic[t] && p < 120) { path[p++] = topic[t++]; }
path[p++] = '.';
path[p++] = '0' + s;
path[p] = '\0';
handle = montauk::open(path);
if (handle >= 0) {
foundSection = s;
break;
}
}
}
if (handle < 0) {
montauk::print("No manual entry for ");
montauk::print(topic);
montauk::putchar('\n');
return;
}
// Load entire file into heap
uint64_t fileSize = montauk::getsize(handle);
if (fileSize == 0) {
montauk::close(handle);
montauk::print("Empty manual page.\n");
return;
}
char* fileData = (char*)montauk::malloc(fileSize + 1);
if (fileData == nullptr) {
montauk::close(handle);
montauk::print("Out of memory.\n");
return;
}
uint64_t offset = 0;
while (offset < fileSize) {
uint64_t chunk = fileSize - offset;
if (chunk > 4096) chunk = 4096;
int bytesRead = montauk::read(handle, (uint8_t*)fileData + offset, offset, chunk);
if (bytesRead <= 0) break;
offset += bytesRead;
}
fileData[offset] = '\0';
montauk::close(handle);
// Parse into lines
ManLine* lines = (ManLine*)montauk::malloc(MAN_MAX_LINES * sizeof(ManLine));
if (lines == nullptr) {
montauk::mfree(fileData);
montauk::print("Out of memory.\n");
return;
}
int totalLines = 0;
const char* p = fileData;
while (*p && totalLines < MAN_MAX_LINES) {
const char* lineStart = p;
while (*p && *p != '\n') p++;
int lineLen = (int)(p - lineStart);
if (*p == '\n') p++;
ManLine& ln = lines[totalLines];
ln.isSH = false;
ln.isSS = false;
ln.isBold = false;
ln.isTH = false;
if (starts_with(lineStart, ".TH ")) {
ln.isTH = true;
ln.text = lineStart + 4;
ln.len = lineLen - 4;
} else if (starts_with(lineStart, ".SH ")) {
ln.isSH = true;
ln.text = lineStart + 4;
ln.len = lineLen - 4;
} else if (starts_with(lineStart, ".SS ")) {
ln.isSS = true;
ln.text = lineStart + 4;
ln.len = lineLen - 4;
} else if (starts_with(lineStart, ".B ")) {
ln.isBold = true;
ln.text = lineStart + 3;
ln.len = lineLen - 3;
} else if (starts_with(lineStart, ".BI ")) {
ln.isBold = true;
ln.text = lineStart + 4;
ln.len = lineLen - 4;
} else {
ln.text = lineStart;
ln.len = lineLen;
}
totalLines++;
}
if (totalLines == 0) {
montauk::mfree(lines);
montauk::mfree(fileData);
montauk::print("Empty manual page.\n");
return;
}
// Get terminal dimensions
int cols = 80, rows = 25;
montauk::termsize(&cols, &rows);
// Enter alternate screen, hide cursor
montauk::print("\033[?1049h");
montauk::print("\033[?25l");
int scroll = 0;
int maxScroll = totalLines - (rows - 1);
if (maxScroll < 0) maxScroll = 0;
man_render(lines, totalLines, scroll, rows, cols, topic, foundSection);
// Event loop — yield while waiting for key input
bool running = true;
while (running) {
while (!montauk::is_key_available()) {
montauk::yield();
}
montauk::abi::KeyEvent ev;
montauk::getkey(&ev);
if (!ev.pressed) continue;
int contentRows = rows - 1;
switch (ev.ascii) {
case 'q':
running = false;
break;
case 'j':
if (scroll < maxScroll) scroll++;
break;
case 'k':
if (scroll > 0) scroll--;
break;
case ' ':
scroll += contentRows;
if (scroll > maxScroll) scroll = maxScroll;
break;
case 'b':
scroll -= contentRows;
if (scroll < 0) scroll = 0;
break;
case 'g':
scroll = 0;
break;
case 'G':
scroll = maxScroll;
break;
default:
// Handle scancodes for special keys
switch (ev.scancode) {
case 0x48: // Up arrow
if (scroll > 0) scroll--;
break;
case 0x50: // Down arrow
if (scroll < maxScroll) scroll++;
break;
case 0x49: // Page Up
scroll -= contentRows;
if (scroll < 0) scroll = 0;
break;
case 0x51: // Page Down
scroll += contentRows;
if (scroll > maxScroll) scroll = maxScroll;
break;
case 0x47: // Home
scroll = 0;
break;
case 0x4F: // End
scroll = maxScroll;
break;
}
break;
}
if (running) {
man_render(lines, totalLines, scroll, rows, cols, topic, foundSection);
}
}
// Restore screen
montauk::print("\033[?25h");
montauk::print("\033[?1049l");
montauk::mfree(lines);
montauk::mfree(fileData);
}