add client/server (not tested yet)

client.c

@@ -0,0 +1,176 @@
+/*
+ * This file is part of the CCD_Capture project.
+ * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+// client-side functions
+#include <math.h>  // isnan
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <usefull_macros.h>
+
+#include "client.h"
+#include "cmdlnopts.h"
+#include "server.h" // for common commands names
+#include "socket.h"
+
+static char sendbuf[BUFSIZ];
+#define SENDMSG(...) do{snprintf(sendbuf, BUFSIZ-1, __VA_ARGS__); verbose(2, "%s", sendbuf); sendstrmessage(sock, sendbuf); getans(sock);}while(0)
+
+/**
+ * check data from  fd (polling function for client)
+ * @param fd - file descriptor
+ * @return 0 in case of timeout, 1 in case of fd have data, -1 if error
+ */
+static int canberead(int fd){
+    fd_set fds;
+    struct timeval timeout;
+    timeout.tv_sec = 0;
+    timeout.tv_usec = 100;
+    FD_ZERO(&fds);
+    FD_SET(fd, &fds);
+    do{
+        int rc = select(fd+1, &fds, NULL, NULL, &timeout);
+        if(rc < 0){
+            if(errno != EINTR){
+                LOGWARN("select()");
+                WARN("select()");
+                return -1;
+            }
+            continue;
+        }
+        break;
+    }while(1);
+    if(FD_ISSET(fd, &fds)){
+        return 1;
+    }
+    return 0;
+}
+
+static char *getans(int sock){
+    static char buf[BUFSIZ];
+    double t0 = dtime();
+    char *ans = NULL;
+    while(dtime() - t0 < ANSWER_TIMEOUT){
+        if(1 != canberead(sock)) continue;
+        int n = read(sock, buf, BUFSIZ-1);
+        if(n == 0){
+            WARNX("Server disconnected");
+            signals(1);
+        }
+        ans = buf;
+        buf[n] = 0;
+        DBG("Got from server: %s", buf);
+        verbose(1, "%s", buf);
+    }
+    return ans;
+}
+
+static char *makeabspath(const char *path){
+    static char buf[PATH_MAX];
+    if(!path) return NULL;
+    char *ret = NULL;
+    int unl = 0;
+    FILE *f = fopen(path, "r");
+    if(!f){
+        f = fopen(path, "a");
+        if(!f){
+            ERR("Can't create %s", path);
+            return NULL;
+        }
+        unl = 1;
+    }
+    if(!realpath(path, buf)){
+        ERR("realpath()");
+    }else ret = buf;
+    fclose(f);
+    if(unl) unlink(path);
+    return ret;
+}
+
+/**
+ * @brief processData - process here some actions and make messages for server
+ */
+static void process_data(int sock){
+    // focuser
+    if(GP->listdevices) SENDMSG(CMD_FOCLIST);
+    if(GP->focdevno > -1) SENDMSG(CMD_FDEVNO "=%d", GP->focdevno);
+    if(!isnan(GP->gotopos)){
+        SENDMSG(CMD_FGOTO "=%g", GP->gotopos);
+    }
+    // wheel
+    if(GP->listdevices) SENDMSG(CMD_WLIST);
+    if(GP->whldevno > -1) SENDMSG(CMD_WDEVNO "=%d", GP->whldevno);
+    if(GP->setwheel > -1) SENDMSG(CMD_WPOS "=%d", GP->setwheel);
+    // CCD/CMOS
+    if(GP->cancelexpose) SENDMSG(CMD_EXPSTATE "=%d", CAMERA_IDLE);
+    if(GP->listdevices) SENDMSG(CMD_CAMLIST);
+    if(GP->camdevno > -1) SENDMSG(CMD_CAMDEVNO "=%d", GP->camdevno);
+    if(GP->hbin) SENDMSG(CMD_HBIN "=%d", GP->hbin);
+    if(GP->vbin) SENDMSG(CMD_VBIN "=%d", GP->vbin);
+    if(!isnan(GP->temperature)) SENDMSG(CMD_CAMTEMPER "=%g", GP->temperature);
+    if(GP->shtr_cmd > -1) SENDMSG(CMD_SHUTTER "=%d", GP->shtr_cmd);
+    if(GP->confio > -1) SENDMSG(CMD_CONFIO "=%d", GP->confio);
+    if(GP->setio > -1) SENDMSG(CMD_IO "=%d", GP->setio);\
+    if(!isnan(GP->gain)) SENDMSG(CMD_GAIN "=%g", GP->gain);
+    if(!isnan(GP->brightness)) SENDMSG(CMD_BRIGHTNESS "=%g", GP->brightness);
+    if(GP->nflushes > 0) SENDMSG(CMD_NFLUSHES "=%d", GP->nflushes);
+    if(GP->rewrite) SENDMSG(CMD_REWRITE "=1");
+    else SENDMSG(CMD_REWRITE "=0");
+    if(GP->outfile) SENDMSG(CMD_FILENAME "=%s", makeabspath(GP->outfile));
+    if(GP->outfileprefix) SENDMSG(CMD_FILENAMEPREFIX "=%s", makeabspath(GP->outfileprefix));
+    // if client gives filename and exptime, make exposition
+    if(GP->exptime > -DBL_EPSILON){
+        SENDMSG(CMD_EXPOSITION "=%g", GP->exptime);
+        if(GP->outfile || GP->outfileprefix) SENDMSG(CMD_EXPSTATE "=%d", CAMERA_CAPTURE);
+    }
+    // common information
+    SENDMSG(CMD_INFO);
+}
+
+void client(int sock){
+    process_data(sock);
+    if(!GP->waitexpend) return;
+    double t0 = dtime(), tw = t0;
+    while(dtime() - t0 < CLIENT_TIMEOUT){
+        if(GP->waitexpend && dtime() - tw > WAIT_TIMEOUT){
+            SENDMSG(CMD_TREMAIN); // get remained time
+            tw = dtime();
+            sprintf(sendbuf, "%s", CMD_EXPSTATE);
+            verbose(2, "%s", sendbuf);
+            sendstrmessage(sock, sendbuf);
+        }
+        char *ans = getans(sock);
+        if(ans){
+            t0 = dtime();
+            char *val = get_keyval(ans);
+            if(val && 0 == strcmp(ans, CMD_EXPSTATE)){
+                int state = atoi(val);
+                if(state == CAMERA_ERROR){
+                    WARNX(_("Can't make exposition"));
+                    return;
+                }
+                if(state != CAMERA_CAPTURE){
+                    verbose(2, "Frame ready!");
+                    return;
+                }
+            }
+        }
+    }
+    WARNX(_("Server timeout"));
+    DBG("Timeout");
+}