basic support for terminal resizing

Not realtime, the size change is detected and used on the next run.

This definitely doesn't handle everything, but it at
least makes things print correctly on the next run.

Though there can still be some garbage-looking output above the printed
output when it doesn't take up the full screen.

CHANGELOG.md

@@ -4,6 +4,14 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+### Added
+
+- Basic support for reacting to terminal resizes.
+
+### Fixed
+
+- Fix for output not ending in a newline.
+
 ## [1.3] - 2019-11-29
 
 ### Changed

src/main.c

@@ -10,6 +10,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/ioctl.h>
 #include <sys/wait.h>
 #include <term.h>
 #include <unistd.h>
@@ -19,6 +20,7 @@
 char *program_name = PROGRAM_NAME;
 
 bool truncate_lines = false;
+int s_lines, s_cols;
 
 int abort_ltz(int res) {
  if (res < 0) {
@@ -89,16 +91,16 @@ ssize_t read_line(FILE *s, size_t max_display_len) {
 // Read the file stream and show the first page of output.
 void read_show_output(FILE *s, size_t *count, size_t *shown, size_t *total) {
  termput0("cd");
- int lines_left = LINES - 2;
+ int lines_left = s_lines - 2;
  for (;;) {
  ssize_t display_len =
- read_line(s, truncate_lines ? COLS : COLS * lines_left);
+ read_line(s, truncate_lines ? s_cols : s_cols * lines_left);
  if (display_len < 0)
  break;
  *total += 1;
  if (lines_left > 0) {
  *count += 1;
- int nlines = (int)ceil((double)display_len / COLS);
+ int nlines = (int)ceil((double)display_len / s_cols);
  lines_left -= nlines;
  *shown += nlines;
  }
@@ -151,6 +153,12 @@ int read_command(const char *command, size_t *count, size_t *shown, size_t *tota
 // Run the current command string and display the first page of results.
 // Args are passed in by readline and ignored.
 int show_preview(const char *a, int b) {
+ // Get the current window dimensions
+ struct winsize sizes;
+ abort_ltz(ioctl(0, TIOCGWINSZ, &sizes));
+ s_lines = sizes.ws_row;
+ s_cols = sizes.ws_col;
+
  printf("\n");
  size_t count = 0;
  size_t shown = 0;
@@ -163,7 +171,7 @@ int show_preview(const char *a, int b) {
  } else {
  statsize = printf(" error in command: %i ", last_status);
  }
- printf("%*s", COLS - statsize, "");
+ printf("%*s", s_cols - statsize, "");
  termput0("me");
  termput1("UP", shown + 1);
  // moving the cursor fully left, necessary for libreadline but not libedit
@@ -217,7 +225,7 @@ void version() {
 int main(int argc, char *const *argv) {
  if (argc)
  program_name = argv[0];
- char *locale = setlocale(LC_ALL, "");
+ setlocale(LC_ALL, "");
  int c;
  while ((c = getopt_long(argc, argv, "thv", long_options, NULL)) != -1) {
  switch (c) {