Linux Libraries - Revision history

Heth: /* Sourcefile containing main */

2023-10-25T05:51:16Z

‎Sourcefile containing main

Heth: /* Source files */

2023-10-25T05:50:01Z

‎Source files

Heth at 09:49, 25 November 2020

2020-11-25T09:49:37Z

Heth at 11:46, 22 November 2020

2020-11-22T11:46:09Z

Heth: /* Compiling and linking */

2018-12-23T15:19:28Z

‎Compiling and linking

Heth: /* Compiling and linking */

2018-12-23T15:16:57Z

‎Compiling and linking

Heth: /* Using the archive */

2018-12-23T15:13:34Z

‎Using the archive

Heth: /* Compiling and linking */

2018-12-23T14:54:55Z

‎Compiling and linking

Heth: /* Compiling and linking */

2018-12-23T12:29:11Z

‎Compiling and linking

Heth at 12:25, 23 December 2018

2018-12-23T12:25:52Z

@@ Line 59: / Line 59: @@
          p1();
          p2();
          return(0);
+}

@@ Line 2: / Line 2: @@
 =Source files=
 The following four sourcefiles are used:
-*file1.c is quite small
+*file1.c contains a const array of '''one''' megabyte
-*file2.c contains a const array of '''one''' megabyte
+*file2.c is quite small
 *file3.c contains a const array of '''two''' megabyte
 *hi.c contains main and uses functions from ''file1.c'' and ''file2.c'' but not ''file3.c''

@@ Line 157: / Line 157: @@
 -rwxrwxr-x. 1 heth heth 3162256 Dec 23 13:17 libshared.so
 </source>
-[[Category:Linux]][[Category:Linux Programming]]
+[[Category:Linux]][[Category:Linux Programming]][[Category:C]]

@@ Line 53: / Line 53: @@
 extern void p1( void );
 extern void p2( void );
 int main( void ) {
@@ Line 58: / Line 59: @@
          p1();
          p2();
          return(0);
+}

@@ Line 135: / Line 135: @@
 ===Compiling and linking===
 <source lang=bash>
-[heth@localhost libleg]$ gcc hi.c -lshared -L. -I. -o hi
+[heth@localhost libleg]$ gcc hi.c -lshared -L. -o hi
 [heth@localhost libleg]$ LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH ./hi
 Starting main

@@ Line 130: / Line 130: @@
 </source>
 ==Using the archive==
-Shared library files are normally kept in a ''/usr/lib'' directory and called ''.so'' (Shared Obkect). Actual path can be seen in ''/etc/ld.so.conf''. In our example the the we add the path to our ''.so'' file in the working directory.
+Shared library files are normally kept in a ''/usr/lib'' subdirectory and called ''.so'' (Shared Obkect). Actual path can be seen in ''/etc/ld.so.conf''. In our example the the we add the path to our ''.so'' file in the working directory.

← Older revision		Revision as of 12:25, 23 December 2018
Line 111:		Line 111:

	=Shared example=		=Shared example=
		+	Shared libraries are linked at compile time - meaning that all binaries that use a shared library can be updated by updating the shared library only.
		+	See example below.
		+	==Creating libfilearchive.a==
		+	Notice the size of the object files from and the size of the ''.so'' shared library file. It contains all three ''.o'' files.
		+	<source lang=bash>
		+	[heth@localhost ]$ gcc -fPIC -c file1.c
		+	[heth@localhost ]$ gcc -fPIC -c file2.c
		+	[heth@localhost ]$ gcc -fPIC -c file3.c
		+	[heth@localhost ]$ gcc -shared -o libshared.so file1.o file2.o file3.o
		+	[heth@localhost ]$ ls -l
		+	-rw-rw-r--. 1 heth heth 334 Dec 23 10:32 file1.c
		+	-rw-rw-r--. 1 heth heth 1050288 Dec 23 10:32 file1.o
		+	-rw-rw-r--. 1 heth heth 125 Dec 23 10:26 file2.c
		+	-rw-rw-r--. 1 heth heth 1536 Dec 23 10:31 file2.o
		+	-rw-rw-r--. 1 heth heth 345 Dec 23 10:39 file3.c
		+	-rw-rw-r--. 1 heth heth 2098864 Dec 23 10:40 file3.o
		+	-rw-rw-r--. 1 heth heth 3162256 Dec 23 13:17 libshared.so
		+	</source>
		+	==Using the archive==
		+	Shared library files are normally kept in a ''/usr/lib'' directory and called ''.so'' (Shared Obkect). Actual path can be seen in ''/etc/ld.so.conf''. In our example the the we add the path to our ''.so'' file in the working directory.
		+
		+
		+	===Compiling and linking===
		+	<source lang=bash>
		+	[heth@localhost libleg]$ gcc hi.c -lfilearchive -L. -o hi
		+	[heth@localhost libleg]$ LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH ./hi
		+	Starting main
		+	=============
		+
		+	I am file1
		+	txt is 1048576 bytes
		+	I am file2
		+	[heth@localhost libleg]$ ls -l
		+	total 18524
		+	-rw-rw-r--. 1 heth heth 334 Dec 23 10:32 file1.c
		+	-rw-rw-r--. 1 heth heth 1050288 Dec 23 11:42 file1.o
		+	-rw-rw-r--. 1 heth heth 125 Dec 23 10:26 file2.c
		+	-rw-rw-r--. 1 heth heth 1536 Dec 23 11:42 file2.o
		+	-rw-rw-r--. 1 heth heth 345 Dec 23 10:39 file3.c
		+	-rw-rw-r--. 1 heth heth 2098864 Dec 23 11:42 file3.o
		+	-rwxrwxr-x. 1 heth heth 1067104 Dec 23 13:24 hi
		+	-rw-rw-r--. 1 heth heth 219 Dec 23 11:24 hi.c
		+	-rwxrwxr-x. 1 heth heth 3162256 Dec 23 13:17 libshared.so
		+	</source>
	[[Category:Linux]]		[[Category:Linux]]