From 60791062ac4f87b599e4fa12a7dfadf71d072c29 Mon Sep 17 00:00:00 2001
From: Stefan Schippers <stefan.schippers@gmail.com>
Date: Mon, 31 Aug 2020 21:24:03 +0200
Subject: [PATCH] added -b/--batch cmd option (__unix__ only) to detach xschem
 completely from console

---
 doc/manpages/xschem.1.in       |  4 ++++
 doc/xschem_man/run_xschem.html |  1 +
 src/globals.c                  |  2 +-
 src/main.c                     | 32 ++++++++++++++++++++++++++++----
 src/options.c                  |  3 +++
 src/xinit.c                    |  6 +++++-
 src/xschem.h                   |  2 +-
 src/xschem.help                |  1 +
 8 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/doc/manpages/xschem.1.in b/doc/manpages/xschem.1.in
index 4fa3f078..641166c3 100644
--- a/doc/manpages/xschem.1.in
+++ b/doc/manpages/xschem.1.in
@@ -38,6 +38,10 @@ hierarchical representation of circuits with a top down approach.
 Print help and exit.
 .TP
 
+.B -n, --batch
+Detach xschem from console.
+.TP
+
 .B -n, --netlist
 Do a netlist of the given schematic cell.
 .TP
diff --git a/doc/xschem_man/run_xschem.html b/doc/xschem_man/run_xschem.html
index 42ea25a7..e2e08dd3 100644
--- a/doc/xschem_man/run_xschem.html
+++ b/doc/xschem_man/run_xschem.html
@@ -47,6 +47,7 @@ user:~$ xschem .../xschem_library/examples/0_examples_top.sch
 usage: xschem [options] [schematic | symbol ]
 Options:
   -h  --help           Print this help.
+  -b  --batch          Detach Xschem from console.
   -n  --netlist        Do a netlist of the given schematic cell.
   -v  --version        Print version information and exit.
   -V  --vhdl           Set netlist type to VHDL.
diff --git a/src/globals.c b/src/globals.c
index 1eb50303..a4783ef5 100644
--- a/src/globals.c
+++ b/src/globals.c
@@ -268,7 +268,7 @@ struct wireentry *wiretable[NBOXES][NBOXES];
 struct instentry *insttable[NBOXES][NBOXES];
 size_t get_tok_value_size;
 size_t get_tok_size;
-
+int batch_mode = 0; /* no tcl console if set; batch mode */
 
 #ifdef HAS_CAIRO
 cairo_surface_t *sfc, *save_sfc;
diff --git a/src/main.c b/src/main.c
index cc427134..7ebc1580 100644
--- a/src/main.c
+++ b/src/main.c
@@ -26,10 +26,10 @@
 #endif
 
 void sig_handler(int s){
-  #ifndef IN_MEMORY_UNDO
+#ifndef IN_MEMORY_UNDO
   char emergency_prefix[PATH_MAX];
   const char *emergency_dir;
-  #endif
+#endif
 
   /* 20150410 */
   if(s==SIGINT) {
@@ -37,7 +37,7 @@ void sig_handler(int s){
     return;
   }
 
-  #ifndef IN_MEMORY_UNDO
+#ifndef IN_MEMORY_UNDO
   /* 20180923 no more mkdtemp */
   my_snprintf(emergency_prefix, S(emergency_prefix), "xschem_emergencysave_%s_", 
            skip_dir(schematic[currentsch]));
@@ -51,7 +51,7 @@ void sig_handler(int s){
     fprintf(errfp, "rename dir %s to %s failed\n", undo_dirname, emergency_dir);
   }
   fprintf(errfp, "EMERGENCY SAVE DIR: %s\n", emergency_dir);
-  #endif
+#endif
   fprintf(errfp, "\nFATAL: signal %d\n", s);
   fprintf(errfp, "while editing: %s\n", skip_dir(schematic[currentsch]));
   exit(EXIT_FAILURE);
@@ -84,6 +84,30 @@ int main(int argc, char **argv)
   if(debug_var>=1 && !has_x) 
     fprintf(errfp, "main(): no DISPLAY set, assuming no X available\n");
 
+/* detach from console (fork a child and close std file descriptors) */
+#ifdef __unix__
+  if(batch_mode) {
+    pid_t pid = fork();
+    if(pid < 0) {
+      fprintf(errfp, "main(): fork() failed\n");
+      exit(EXIT_FAILURE);
+    }
+    if(pid == 0) {
+      /* The child becomes the daemon. */
+      /* Detach all standard I/O descriptors */
+      close(0); /* stdin */
+      close(1); /* stdout */
+      close(2); /* stderr */
+      setsid(); /* new session */
+      /* Ok, now detached */
+    }
+    else {
+      /* terminate parent */
+      exit(0);
+    }
+  }
+#endif
+
   if(has_x) Tk_Main(1, argv, Tcl_AppInit);
   else     Tcl_Main(1, argv, Tcl_AppInit);
   return 0;
diff --git a/src/options.c b/src/options.c
index be2fc981..30793e59 100644
--- a/src/options.c
+++ b/src/options.c
@@ -129,6 +129,9 @@ void check_opt(char *opt, char *optval, int type)
         dbg(1, "process_options(): set netlist type to verilog\n");
         netlist_type=CAD_VERILOG_NETLIST;
 
+    } else if( (type == SHORT && *opt == 'b') || (type == LONG && !strcmp("batch", opt)) ) {
+        batch_mode = 1;
+
     } else if( (type == SHORT && *opt == 'v') || (type == LONG && !strcmp("version", opt)) ) {
         print_version();
 
diff --git a/src/xinit.c b/src/xinit.c
index 3d4f00e9..343282b6 100644
--- a/src/xinit.c
+++ b/src/xinit.c
@@ -1454,7 +1454,11 @@ int Tcl_AppInit(Tcl_Interp *inter)
  /* */
 
 
- if(!no_readline) {
+ if(
+#ifdef __unix__
+    !batch_mode && 
+#endif
+    !no_readline) {
    tcleval( "if {![catch {package require tclreadline}]} "
       "{::tclreadline::readline customcompleter  completer; ::tclreadline::Loop }" ) ;
  }
diff --git a/src/xschem.h b/src/xschem.h
index a2d448db..bc4a2355 100644
--- a/src/xschem.h
+++ b/src/xschem.h
@@ -674,7 +674,7 @@ extern double mx_double_save, my_double_save; /*  20070322 */
 extern struct instentry *insttable[NBOXES][NBOXES];
 extern size_t get_tok_value_size;
 extern size_t get_tok_size;
-
+extern int batch_mode; /* no TCL console */
 /*  functions */
 extern void dbg(int level, char *fmt, ...);
 extern void here(void);
diff --git a/src/xschem.help b/src/xschem.help
index ab7884b8..9308040b 100644
--- a/src/xschem.help
+++ b/src/xschem.help
@@ -1,6 +1,7 @@
 usage: xschem [options] [schematic | symbol ]
 Options:
   -h  --help           Print this help.
+  -b  --batch          Detach Xschem from console.
   -n  --netlist        Do a netlist of the given schematic cell.
   -v  --version        Print version information and exit.
   -V  --vhdl           Set netlist type to VHDL.