redirect stdout to a file

FILE * fp = fopen(“myfile.txt","w+a") ;
int fd= -1;
if ( fp != NULL ) dup2(fd,1) ; // 1 for stdout
if ( fd < 0 ) return false ; // fail
else return true ; // success
close(fd);
fclose(fp);

blit banchmark on each platform

ref:

http://www.rocklyte.com/news_20030917.html

make file link with dynamic and static libraries

• to build static library

% gcc -c libtest.c -o libtest.o
% ar rcs libtest.a libtest.o

• to build dynamic library

-fPIC option tells gcc to create position independant code which is necessary for shared libraries

% gcc -c -fPIC libtest.c -o libtest.o
% gcc -shared -o libtest.so libtest.o

• to use static library

% gcc -static main.c -L. -ltest -o testStatic

• to use dynamic library

% gcc main.c -L. -ltest -o testDynamic

the source file of application who uses the library ltest, sould be located before -l options
-L<path to search libraries> (no spacing after -L)
-o <output file>
-l<lib_name> (no spacing after -l)

in static link, library name is lib.a ex: libtest.a libcheckitout.a or libxxxx.a

in dynamic link, library start with lib ex: libtest or libtest.so or lib….

gcc [options] -o

warning: control may reach end of non-void function

because the called function declared as the non-void (ex: int add(int a,int b) ) but in the called function it has no “return" value.

order of link libraries in makefile

example:
libabc.a is an user make library, in this lib, use a function pow in linux lib -lm.
in makefile you should
$(CC) -o a.out -labc -lm
if you
$(CC) -o a.out -lm -labc
there would be an link error

EM8621L get media duration

1. to get mp4′s duration, open track video/audio first.

stray ‘\’ in program

problem
compiling error:

mmi_gfx_macro.h:21: parse error before `{‘
mmi_gfx_macro.h:21: stray ‘\’ in program
mmi_gfx_macro.h:22: stray ‘\’ in program

root cause
Possibly \ at “end" of a CRLF terminated line is not seen as
line-continued?
solution:
%dos2unix <your_c_file>

Build php with thttpd

Steps:

1. build php with configuration –with-thttpd=<thttpd_src_folder>
   ./configure –with-thttpd=<thttpd_src_folder>
   make all; make install
2. in thttpd source folder
   ./configure
   make all; make install

Remarks:

• php5.x with thttpd –> 3.xMB
• php4.x with thttpd –> 1.xMB

Reference:
http://www.phpe.net/manual/install.linux.php