util.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <termios.h>
   5 #include <unistd.h>
   6
   7 #include "util.h"
   8
   9
  10 /*
  11  * Reset the terminal state and exit with error.
  12  */
  13 void
  14 die(const char *s)
  15 {
  16         /* tcsetattr(STDIN_FILENO, TCSANOW, &termio_old); */
  17         fprintf(stderr, "%s\n", s);
  18         exit(EXIT_FAILURE);
  19 }
  20
  21
  22 /*
  23  * Set terminal to send one char at a time for interactive mode, and return the
  24  * last terminal state.
  25  */
  26 struct termios
  27 set_terminal(int tty_fd)
  28 {
  29         struct termios termio_old;
  30         struct termios termio_new;
  31
  32         /* set the terminal to send one key at a time. */
  33
  34         /* get the terminal's state */
  35         if (tcgetattr(tty_fd, &termio_old) < 0) {
  36                 die("Can not get terminal attributes with tcgetattr().");
  37         }
  38
  39         /* create a new modified state by switching the binary flags */
  40         termio_new          = termio_old;
  41         termio_new.c_lflag &= ~(ICANON | ECHO | IGNBRK);
  42
  43         /* apply this state to current terminal now (TCSANOW) */
  44         tcsetattr(tty_fd, TCSANOW, &termio_new);
  45
  46         return termio_old;
  47 }
  48
  49
  50 /*
  51  * Replace tab as a multiple of 8 spaces in a line.
  52  *
  53  * Allocates memory.
  54  */
  55 char *
  56 expand_tabs(char *line)
  57 {
  58         size_t i, n;
  59         char *converted = malloc(sizeof(char) * (strlen(line) * 8 + 1));
  60
  61         for (i = 0, n = 0; i < strlen(line); i++, n++) {
  62                 if (line[i] == '\t') {
  63                         for (; n == 0 || n % 8 != 0; n++)
  64                                 converted[n] = ' ';
  65                         n--;
  66                 } else {
  67                         converted[n] = line[i];
  68                 }
  69         }
  70
  71         converted[n] = '\0';
  72
  73         return converted;
  74 }