feat(connect): initial commit

connect/main.c

@@ -0,0 +1,60 @@
+#include <stdio.h>
+#include <libpq-fe.h>
+
+int pg_connect(char* conninfo, PGconn** conn)
+{
+
+    *conn = PQconnectdb(conninfo);
+    if (PQstatus(*conn) != CONNECTION_OK) {
+        fprintf(stderr,
+                "ERROR: Connection to database failed: %s",
+                PQerrorMessage(*conn));
+        return 0;
+    }
+
+    return 1;
+}
+
+/* set correctely your values here */
+#define PG_HOST    "127.0.0.1"
+//#define PG_USER    "postgres"
+//#define PG_DB      "postgres"
+//#define PG_PASS    "postgres"
+//#define PG_PORT    5432
+
+int main(int argc, char *argv[])
+{
+  /*declarations*/
+    char        conninfo[250];
+    PGconn     *conn  = NULL;
+
+    sprintf(conninfo,
+            "user=%s password=%s dbname=%s hostaddr=%s port=%d",
+            PG_USER, PG_PASS, PG_DB, PG_HOST, PG_PORT);
+    printf("main() conninfo: %s\n",conninfo);
+
+    if (!pg_connect(conninfo, &conn)) {
+      printf("main() go to end\n");
+      goto end;
+    }else{
+      printf("main() go NOT to end\n");
+    }
+
+    /*
+        Here fit your staff
+     */
+    int isThreadSafe=0;
+    printf("main() Started...\n");
+    isThreadSafe=PQisthreadsafe();
+    if(isThreadSafe==1){
+      printf("main() libpq is thread-safe\n");
+    }else{
+      printf("main() libpq is NOT thread-safe\n");
+    }
+    printf("main() Done.\n");
+
+    end:
+      PQfinish(conn);
+      return 0;
+
+}

connect/makefile

@@ -0,0 +1,24 @@
+# Docu
+#
+#$@ is the name of the file to be made
+#$? is the names of the changed dependents
+#$< the name of the related file that caused the action
+#$* the prefix shared by target and dependent files
+#
+# Others
+RM      = /bin/rm -f
+#
+# Source, Executable, Includes, Library Defines
+EXE    = main
+#
+# Compiler, Linker Defines
+CC      = /usr/bin/gcc
+#
+all: main.o
+	$(CC) main.c -I/usr/include/postgresql -L/usr/lib/x86_64-linux-gnu -lpq -std=c99 -Wall -o $(EXE)
+#
+main.o:
+	$(CC) -c main.c -I/usr/include/postgresql
+# Clean Up Objects, Exectuables, Dumps out of source directory
+clean:
+	$(RM) *.o $(EXE) *~

connect/readme.md

@@ -0,0 +1,19 @@
+* install dependencies on Debian Bullseye
+```
+sudo apt install libpq-dev --no-install-recommends
+```
+
+* build
+```
+make
+```
+
+* run
+```
+./main 'postgresql://<user>:<secret>@<host>:<port>/<database>'
+```
+
+* or run
+```
+./main "host=<host> port=<port> user=<user> password=<<secret>> dbname=<database>"
+```