lchat: exclude filter from input tail pipe - lchat - A line oriented chat front end for ii.
(HTM) git clone git://git.suckless.org/lchat
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---
(DIR) commit e5371dc7ca278ac80852f30b699ae3f0ae8627bf
(DIR) parent 5d78aec7398254c86ce90cb53d750af437f12a75
(HTM) Author: Jan Klemkow <j.klemkow@wemelug.de>
Date: Wed, 22 Feb 2017 21:08:33 +0100
lchat: exclude filter from input tail pipe
This avoids a conflict between .bellmatch and .filter.
Both programs get the same raw input from tail now.
Diffstat:
M lchat.c | 83 ++++++++++++++++++++++++++++---
1 file changed, 77 insertions(+), 6 deletions(-)
---
(DIR) diff --git a/lchat.c b/lchat.c
@@ -119,6 +119,45 @@ line_output(struct slackline *sl, char *file)
}
static void
+fork_filter(int *read, int *write)
+{
+ int fds_read[2]; /* .filter -> lchat */
+ int fds_write[2]; /* lchat -> .filter */
+
+ if (pipe(fds_read) == -1)
+ err(EXIT_FAILURE, "pipe");
+ if (pipe(fds_write) == -1)
+ err(EXIT_FAILURE, "pipe");
+
+ switch (fork()) {
+ case -1:
+ err(EXIT_FAILURE, "fork of .filter");
+ case 0: /* child */
+ if (dup2(fds_read[1], STDOUT_FILENO) == -1)
+ err(EXIT_FAILURE, "dup2");
+ if (dup2(fds_write[0], STDIN_FILENO) == -1)
+ err(EXIT_FAILURE, "dup2");
+
+ if (close(fds_read[0]) == -1)
+ err(EXIT_FAILURE, "close");
+ if (close(fds_write[1]) == -1)
+ err(EXIT_FAILURE, "close");
+
+ execl("./.filter", "./.filter", NULL);
+ err(EXIT_FAILURE, "exec of .filter");
+ }
+
+ /* parent */
+ if (close(fds_read[1]) == -1)
+ err(EXIT_FAILURE, "close");
+ if (close(fds_write[0]) == -1)
+ err(EXIT_FAILURE, "close");
+
+ *read = fds_read[0];
+ *write = fds_write[1];
+}
+
+static void
usage(void)
{
fprintf(stderr, "lchat [-aeh] [-n lines] [-p prompt] [-t title] [-i in]"
@@ -129,11 +168,13 @@ usage(void)
int
main(int argc, char *argv[])
{
- struct pollfd pfd[2];
+ struct pollfd pfd[3];
struct termios term;
struct slackline *sl = sl_init();
int fd = STDIN_FILENO;
int read_fd = 6;
+ int read_filter = -1;
+ int backend_sink = STDOUT_FILENO;
char c;
int ch;
bool empty_line = false;
@@ -260,27 +301,35 @@ main(int argc, char *argv[])
snprintf(tail_cmd, sizeof tail_cmd, "exec tail -n %zd -f %s",
history_len, out_file);
- if (access(".filter", X_OK) == 0)
- strlcat(tail_cmd, " | ./.filter", sizeof tail_cmd);
-
if ((fh = popen(tail_cmd, "r")) == NULL)
err(EXIT_FAILURE, "unable to open pipe to tail");
read_fd = fileno(fh);
}
+ int nfds = 2;
+
pfd[0].fd = fd;
pfd[0].events = POLLIN;
pfd[1].fd = read_fd;
pfd[1].events = POLLIN;
+ if (access(".filter", X_OK) == 0) {
+ fork_filter(&read_filter, &backend_sink);
+
+ pfd[2].fd = read_filter;
+ pfd[2].events = POLLIN;
+
+ nfds = 3;
+ }
+
/* print initial prompt */
fputs(prompt, stdout);
for (;;) {
errno = 0;
- if (poll(pfd, 2, INFTIM) == -1 && errno != EINTR)
+ if (poll(pfd, nfds, INFTIM) == -1 && errno != EINTR)
err(EXIT_FAILURE, "poll");
/* moves cursor back after linewrap */
@@ -338,7 +387,7 @@ main(int argc, char *argv[])
errx(EXIT_FAILURE, "backend exited");
if (n == -1)
err(EXIT_FAILURE, "read");
- if (write(STDOUT_FILENO, buf, n) == -1)
+ if (write(backend_sink, buf, n) == -1)
err(EXIT_FAILURE, "write");
/* terminate the input buffer with NUL */
@@ -348,6 +397,28 @@ main(int argc, char *argv[])
if (bell_flag && bell_match(buf, bell_file))
putchar('\a');
}
+
+ /* handel optional .filter i/o */
+ if (nfds > 2) {
+ /* handle .filter error and its broken pipe */
+ if (pfd[2].revents & POLLHUP)
+ break;
+ if (pfd[2].revents & POLLERR ||
+ pfd[2].revents & POLLNVAL)
+ errx(EXIT_FAILURE, ".filter error");
+
+ /* handle .filter output */
+ if (pfd[2].revents & POLLIN) {
+ char buf[BUFSIZ];
+ ssize_t n = read(pfd[2].fd, buf, sizeof buf);
+ if (n == 0)
+ errx(EXIT_FAILURE, ".filter exited");
+ if (n == -1)
+ err(EXIT_FAILURE, "read");
+ if (write(STDOUT_FILENO, buf, n) == -1)
+ err(EXIT_FAILURE, "write");
+ }
+ }
out:
/* show current input line */
fputs(prompt, stdout);