feat: add lib-version

lib-version/main.c

@@ -0,0 +1,9 @@
+#include <stdio.h>
+#include <libpq-fe.h>
+int main() {
+  int lib_ver = PQlibVersion();
+  printf("Version of libpq: %d\n", lib_ver);
+  printf("Version of libpq: %d\n", lib_ver);
+  printf("Version of libpq: %d\n", lib_ver);
+  return 0;
+}

lib-version/makefile

@@ -0,0 +1,21 @@
+# 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:
+	$(CC) main.c -I/usr/include/postgresql -L/usr/lib/x86_64-linux-gnu -lpq -std=c99 -Wall -o $(EXE)
+# Clean Up Objects, Exectuables, Dumps out of source directory
+clean:
+	$(RM) *.o $(EXE) *~

lib-version/makefile-fail

@@ -0,0 +1,39 @@
+# 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
+#
+#CFLAGS:Extra flags to give to the C compiler
+#LDFLAGS:Extra flags to give to compilers when they are supposed to invoke the linker, `ld'.
+#
+# Source, Executable, Includes, Library Defines
+INCL   =
+SRC    = main.c
+OBJ    = $(SRC:.c=.o)
+LIBS   = -lpq
+EXE    = main
+INC    = -I. -I$(pg_config --includedir)
+
+# Compiler, Linker Defines
+CC      = /usr/bin/gcc
+CFLAGS  = -std=c99 -Wall
+LIBPATH = -L. -L$(pg_config --libdir)
+LDFLAGS = -o $(EXE) $(LIBPATH) $(LIBS)
+RM      = /bin/rm -f
+
+# Compile and Assemble C Source Files into Object Files
+%.o: %.c
+	$(CC) $(INC) $(CFLAGS) -c $*.c
+
+# Link all Object Files with external Libraries into Binaries
+$(EXE): $(OBJ)
+	$(CC) $(LDFLAGS) $(OBJ)
+
+# Objects depend on these Libraries
+$(OBJ): $(INCL)
+
+# Clean Up Objects, Exectuables, Dumps out of source directory
+clean:
+	$(RM) $(OBJ) $(EXE)

lib-version/makefile-fail-2

@@ -0,0 +1,21 @@
+# 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)
+# Clean Up Objects, Exectuables, Dumps out of source directory
+clean:
+	$(RM) *.o $(EXE) *~

lib-version/makefile-fine

@@ -0,0 +1,21 @@
+# 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:
+	$(CC) main.c -I/usr/include/postgresql -L/usr/lib/x86_64-linux-gnu -lpq -std=c99 -Wall -o $(EXE)
+# Clean Up Objects, Exectuables, Dumps out of source directory
+clean:
+	$(RM) *.o $(EXE) *~

lib-version/readme.md

@@ -0,0 +1,5 @@
+* build instruction
+
+```
+gcc -o main main.c -I/usr/include/postgresql -L/usr/lib/x86_64-linux-gnu -lpq -std=c99
+```