Add scape sequence and an option to ignore it

[can-benchmark.git] / utils / sterm.c

diff --git a/utils/sterm.c b/utils/sterm.c
index bbd80dab6d980eb84ac2a58cb340c065bf18e646..ee7f8d70433e64d47db376efa2925dd188bbd5ee 100644 (file)
--- a/utils/sterm.c
+++ b/utils/sterm.c
@@ -1,10 +1,5 @@
 /*
- * Simple terminal
- *
- * This is a minimalist terminal program like minicom or cu. The only
- * thing it does is creating a bidirectional connection between
- * stdin/stdout and a device (e.g. serial terminal). It can also set
- * serial line baudrate and manipulate DTR/RTS modem lines.
+ * Simple serial terminal
  *
  * Copyright 2014 Michal Sojka <sojkam1@fel.cvut.cz>
  *
@@ -23,6 +18,17 @@
  * <http://www.gnu.org/licenses/>.
  */
 
+/*
+ * This is a minimalist terminal program like minicom or cu. The only
+ * thing it does is creating a bidirectional connection between
+ * stdin/stdout and a device (e.g. serial terminal). It can also set
+ * serial line baudrate and manipulate DTR/RTS modem lines.
+ *
+ * The -d and -r option create short pulse on DTR/RTS. The lines are
+ * always raised when the device is opened and those options lower the
+ * lines immediately after opening.
+ */
+
 #define _BSD_SOURCE
 #include <sys/ioctl.h>
 #include <unistd.h>
@@ -44,6 +50,7 @@
 #define VERBOSE(format, ...) do { if (verbose) fprintf(stderr, format, ##__VA_ARGS__); } while (0)
 
 bool verbose = false;
+bool exit_on_escape = true;
 
 char template[] = "/var/lock/TMPXXXXXX";
 char lockfile[100];
@@ -64,7 +71,39 @@ void restore_stdin_term()
 
 void sighandler(int arg)
 {
-       exit(0);
+       exit(0); /* Invoke exit handlers */
+}
+
+int dtr_rts_arg(const char option)
+{
+       int val = -1;
+
+       if (optarg) {
+               switch (optarg[0]) {
+               case '+': val = +1; break;
+               case '-': val = -1; break;
+               default:
+                       fprintf(stderr, "Unknown -%c argument: %s", option, optarg);
+                       exit(1);
+               }
+       }
+       return val;
+}
+
+void exit_on_escapeseq(const char *buf, int len)
+{
+       static const char escseq[] = "\r~.";
+       static const char *state = escseq+1;
+       int i;
+
+       for (i = 0; i < len; i++) {
+               if (buf[i] == *state) {
+                       state++;
+                       if (*state == 0)
+                               exit(0);
+               } else
+                       state = escseq;
+       }
 }
 
 
@@ -74,7 +113,6 @@ int main(int argc, char *argv[])
        char *dev = NULL;
        int opt;
        speed_t speed = 0;
-       int ret;
        int dtr = 0, rts = 0;
        struct termios tio;
        bool stdin_tty;
@@ -85,16 +123,12 @@ int main(int argc, char *argv[])
                atexit(restore_stdin_term);
        }
 
-       while ((opt = getopt(argc, argv, "ndrs:v")) != -1) {
+       while ((opt = getopt(argc, argv, "nd::er::s:v")) != -1) {
                switch (opt) {
-               case 'd':
-                       dtr = 1;
-                       break;
-               case 'n':
-                       raw = false;
-               case 'r':
-                       rts = 1;
-                       break;
+               case 'd': dtr = dtr_rts_arg(opt); break;
+               case 'e': exit_on_escape = false; break;
+               case 'n': raw = false; break;
+               case 'r': rts = dtr_rts_arg(opt); break;
                case 's': {
                        int s = atoi(optarg);
                        switch (s) {
@@ -158,9 +192,21 @@ int main(int argc, char *argv[])
                CHECK(write(tmp, pid, strlen(pid)));
                close(tmp);
                snprintf(lockfile, sizeof(lockfile), "/var/lock/LCK..%s", dev + 5);
+       retry:
                if (link(template, lockfile) == -1) {
-                       perror(lockfile);
-                       exit(1);
+                       tmp = CHECK(open(lockfile, O_RDONLY));
+                       CHECK(read(tmp, pid, sizeof(pid)));
+                       close(tmp);
+                       int p = atoi(pid);
+                       char proc[50];
+                       snprintf(proc, sizeof(proc), "/proc/%d", p);
+                       if (access(proc, F_OK) == 0) {
+                               fprintf(stderr, "%s is used by PID %d\n", dev, p);
+                               exit(1);
+                       }
+                       fprintf(stderr, "Stale lock file %s (PID %d) - removing it!\n", lockfile, p);
+                       CHECK(unlink(lockfile));
+                       goto retry;
                }
                rm_file(0, template);
                on_exit(rm_file, lockfile);
@@ -185,13 +231,13 @@ int main(int argc, char *argv[])
 
                if (dtr || rts) {
                        int status;
-                       tio.c_cflag &= ~HUPCL;
+                       /* tio.c_cflag &= ~HUPCL; */ /* Don't lower DTR/RTS on close */
 
                        CHECK(ioctl(fd, TIOCMGET, &status));
-                       if (dtr == +1) status &= ~TIOCM_DTR;
-                       if (dtr == -1) status |=  TIOCM_DTR;
-                       if (rts == +1) status &= ~TIOCM_RTS;
-                       if (rts == -1) status |=  TIOCM_RTS;
+                       if (dtr == -1) status &= ~TIOCM_DTR;
+                       if (dtr == +1) status |=  TIOCM_DTR;
+                       if (rts == -1) status &= ~TIOCM_RTS;
+                       if (rts == +1) status |=  TIOCM_RTS;
                        CHECK(ioctl(fd, TIOCMSET, &status));
                }
 
@@ -217,13 +263,15 @@ int main(int argc, char *argv[])
        VERBOSE("Connected.\n");
        while (1) {
                int r1, r2;
-               ret = CHECK(poll(fds, 2, -1));
+               CHECK(poll(fds, 2, -1));
                if (fds[0].revents & POLLIN) {
                        r1 = CHECK(read(0, buf, sizeof(buf)));
                        if (r1 == 0) {
                                VERBOSE("EOF on stdin\n");
                                break;
                        }
+                       if (exit_on_escape)
+                               exit_on_escapeseq(buf, r1);
                        r2 = CHECK(write(fd, buf, r1));
                        if (r1 != r2) {
                                fprintf(stderr, "Not all data written to %s (%d/%d)\n", dev, r1, r2);