files: allow to abort the reading of slow files with Ctrl+C

This addresses https://savannah.gnu.org/bugs/?44907.

Original-patch-by: Martin van Zijl <martin.vanzijl@gmail.com>
This commit is contained in:
Benno Schulenberg 2019-05-24 19:58:35 +02:00
parent 8550c6bd93
commit ea11709564

View File

@ -32,6 +32,15 @@
#define LOCKBUFSIZE 8192
static bool control_C_was_pressed;
/* Whether ^C was pressed while reading a file. */
/* A signal handler for when ^C is typed while reading from a file. */
RETSIGTYPE cancel_the_reading(int signal)
{
control_C_was_pressed = TRUE;
}
/* Verify that the containing directory of the given filename exists. */
bool has_valid_path(const char *filename)
{
@ -415,6 +424,8 @@ bool open_buffer(const char *filename, bool new_buffer)
int rc;
/* rc == -2 means that we have a new file. -1 means that the
* open() failed. 0 means that the open() succeeded. */
struct sigaction oldaction, newaction;
/* Original and temporary handlers for SIGINT. */
/* Display newlines in filenames as ^J. */
as_an_at = FALSE;
@ -469,8 +480,21 @@ bool open_buffer(const char *filename, bool new_buffer)
/* If we have a non-new file, read it in. Then, if the buffer has
* no stat, update the stat, if applicable. */
if (rc > 0) {
read_file(f, rc, realname, !new_buffer);
#ifndef NANO_TINY
enable_signals();
#endif
/* Set up a signal handler so that ^C will cancel the reading. */
newaction.sa_handler = cancel_the_reading;
newaction.sa_flags = 0;
sigaction(SIGINT, &newaction, &oldaction);
read_file(f, rc, realname, !new_buffer);
/* Restore the original handler for SIGINT. */
sigaction(SIGINT, &oldaction, NULL);
#ifndef NANO_TINY
disable_signals();
if (openfile->current_stat == NULL)
stat_with_alloc(realname, &openfile->current_stat);
#endif
@ -724,8 +748,14 @@ void read_file(FILE *f, int fd, const char *filename, bool undoable)
* of locking it for each single byte that we read from it. */
flockfile(f);
control_C_was_pressed = FALSE;
/* Read the entire file into the new buffer. */
while ((input_int = getc_unlocked(f)) != EOF) {
if (control_C_was_pressed)
break;
input = (char)input_int;
/* If it's a *nix file ("\n") or a DOS file ("\r\n"), and file