I have downloaded the file bwbar-1.2.tar.gz from kernel.org, but when I type make i comes up with an error and it fails to compile..

And the problem is: I really have no clue whatsoever on whats wrong.. Can anyone please help?

I am running:
Rehat 9
gcc 3.2.2

Here is the output:

[root@trinisrv bwbar-1.2]# make
gcc -Wall -O2 -s -o bwbar bwbar.c -lpng
bwbar.c:32:17: png.h: No such file or directory
bwbar.c: In function `write_bar_graph':
bwbar.c:44: syntax error before "palette"
bwbar.c: At top level:
bwbar.c:56: parse error before "png_ptr"
bwbar.c:56: warning: type defaults to `int' in declaration of `png_ptr'
bwbar.c:56: warning: initialization makes integer from pointer without a cast
bwbar.c:56: warning: data definition has no type or storage class
bwbar.c:57: parse error before "info_ptr"
bwbar.c:57: warning: type defaults to `int' in declaration of `info_ptr'
bwbar.c:57: warning: initialization makes integer from pointer without a cast
bwbar.c:57: warning: data definition has no type or storage class
bwbar.c:58: parse error before '*' token
bwbar.c:58: warning: type defaults to `int' in declaration of `border_row'
bwbar.c:58: warning: data definition has no type or storage class
bwbar.c:59: parse error before '*' token
bwbar.c:59: warning: type defaults to `int' in declaration of `bar_row'
bwbar.c:59: warning: data definition has no type or storage class
bwbar.c:60: parse error before '*' token
bwbar.c:60: warning: type defaults to `int' in declaration of `bp'
bwbar.c:60: warning: data definition has no type or storage class
bwbar.c:63: warning: type defaults to `int' in declaration of `bwidth'
bwbar.c:63: `width' undeclared here (not in a function)
bwbar.c:63: `border' undeclared here (not in a function)
bwbar.c:63: warning: data definition has no type or storage class
bwbar.c:64: warning: type defaults to `int' in declaration of `bheight'
bwbar.c:64: `height' undeclared here (not in a function)
bwbar.c:64: `border' undeclared here (not in a function)
bwbar.c:64: warning: data definition has no type or storage class
bwbar.c:66: warning: type defaults to `int' in declaration of `border_row'
bwbar.c:66: conflicting types for `border_row'
bwbar.c:58: previous declaration of `border_row'
bwbar.c:66: `png_byte' undeclared here (not in a function)
bwbar.c:66: warning: data definition has no type or storage class
bwbar.c:67: warning: type defaults to `int' in declaration of `bar_row'
bwbar.c:67: conflicting types for `bar_row'
bwbar.c:59: previous declaration of `bar_row'
bwbar.c:67: `png_byte' undeclared here (not in a function)
bwbar.c:67: warning: data definition has no type or storage class
bwbar.c:69: parse error before "if"
bwbar.c:72: warning: type defaults to `int' in declaration of `png_ptr'
bwbar.c:72: redefinition of `png_ptr'
bwbar.c:56: `png_ptr' previously defined here
bwbar.c:72: warning: implicit declaration of function `png_create_write_struct'
bwbar.c:72: `PNG_LIBPNG_VER_STRING' undeclared here (not in a function)
bwbar.c:73: initializer element is not constant
bwbar.c:73: warning: data definition has no type or storage class
bwbar.c:75: parse error before "if"
bwbar.c:78: warning: type defaults to `int' in declaration of `info_ptr'
bwbar.c:78: redefinition of `info_ptr'
bwbar.c:57: `info_ptr' previously defined here
bwbar.c:78: warning: implicit declaration of function `png_create_info_struct'
bwbar.c:78: initializer element is not constant
bwbar.c:78: warning: data definition has no type or storage class
bwbar.c:79: parse error before "if"
bwbar.c:87: warning: type defaults to `int' in declaration of `png_init_io'
bwbar.c:87: warning: parameter names (without types) in function declaration
bwbar.c:87: warning: data definition has no type or storage class
bwbar.c:89: warning: type defaults to `int' in declaration of `png_set_compression_level'
bwbar.c:89: warning: parameter names (without types) in function declaration
bwbar.c:89: warning: data definition has no type or storage class
bwbar.c:92: parse error before numeric constant
bwbar.c:94: warning: type defaults to `int' in declaration of `png_set_IHDR'
bwbar.c:94: warning: data definition has no type or storage class
bwbar.c:96: parse error before numeric constant
bwbar.c:96: warning: type defaults to `int' in declaration of `png_set_PLTE'
bwbar.c:96: warning: data definition has no type or storage class
bwbar.c:98: warning: type defaults to `int' in declaration of `png_write_info'
bwbar.c:98: warning: parameter names (without types) in function declaration
bwbar.c:98: warning: data definition has no type or storage class
bwbar.c:100: warning: type defaults to `int' in declaration of `png_set_packing'
bwbar.c:100: warning: parameter names (without types) in function declaration
bwbar.c:100: warning: data definition has no type or storage class
bwbar.c:105: parse error before "__extension__"
bwbar.c:105: parse error before "__uint8_t"
bwbar.c:105: warning: type defaults to `int' in declaration of `__s'
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before '}' token
bwbar.c:105: warning: initialization makes pointer from integer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: parse error before "switch"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: conflicting types for `__u'
bwbar.c:105: previous declaration of `__u'
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: redefinition of `__u'
bwbar.c:105: `__u' previously defined here
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: redefinition of `__u'
bwbar.c:105: `__u' previously defined here
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before '->' token
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: redefinition of `__u'
bwbar.c:105: `__u' previously defined here
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: redefinition of `__u'
bwbar.c:105: `__u' previously defined here
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: redefinition of `__u'
bwbar.c:105: `__u' previously defined here
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: redefinition of `__u'
bwbar.c:105: `__u' previously defined here
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: redefinition of `__u'
bwbar.c:105: `__u' previously defined here
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: redefinition of `__u'
bwbar.c:105: `__u' previously defined here
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: redefinition of `__u'
bwbar.c:105: `__u' previously defined here
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: redefinition of `__u'
bwbar.c:105: `__u' previously defined here
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__u'
bwbar.c:105: redefinition of `__u'
bwbar.c:105: `__u' previously defined here
bwbar.c:105: warning: initialization makes integer from pointer without a cast
bwbar.c:105: initializer element is not constant
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before "case"
bwbar.c:105: warning: type defaults to `int' in declaration of `__s'
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before '}' token
bwbar.c:105: parse error before '\x0'
bwbar.c:105: warning: type defaults to `int' in declaration of `__builtin_memset'
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: warning: type defaults to `int' in declaration of `__s'
bwbar.c:105: warning: data definition has no type or storage class
bwbar.c:105: parse error before '}' token
bwbar.c:108: warning: type defaults to `int' in declaration of `bp'
bwbar.c:108: conflicting types for `bp'
bwbar.c:60: previous declaration of `bp'
bwbar.c:108: warning: data definition has no type or storage class
bwbar.c:109: parse error before "for"
bwbar.c:112: warning: type defaults to `int' in declaration of `spacer'
bwbar.c:112: warning: data definition has no type or storage class
bwbar.c:113: parse error before "for"
bwbar.c:115: warning: type defaults to `int' in declaration of `fspacer'
bwbar.c:115: `spacers' undeclared here (not in a function)
bwbar.c:115: warning: data definition has no type or storage class
bwbar.c:116: parse error before "if"
bwbar.c:123: parse error before '++' token
bwbar.c:124: warning: type defaults to `int' in declaration of `spacer'
bwbar.c:124: redefinition of `spacer'
bwbar.c:112: `spacer' previously defined here
bwbar.c:124: initializer element is not constant
bwbar.c:124: warning: data definition has no type or storage class
bwbar.c:125: parse error before '}' token
bwbar.c:139: warning: type defaults to `int' in declaration of `png_write_end'
bwbar.c:139: warning: parameter names (without types) in function declaration
bwbar.c:139: warning: data definition has no type or storage class
bwbar.c:140: warning: type defaults to `int' in declaration of `status'
bwbar.c:140: redefinition of `status'
bwbar.c:61: `status' previously defined here
bwbar.c:140: warning: data definition has no type or storage class
bwbar.c:142: parse error before ':' token
make: *** [bwbar] Error 1

Frequently in C/C++ and many other langues only the first error matters much.
Everything else is a result of that, in this case that holds true.

bwbar.c:32:17: png.h: No such file or directory

You need to install libpng

http://www.libpng.org/pub/png/libpng.html

Hmm.. When i do a rpm -qa | grep png, libpng seems to be installed..

[root@trinisrv root]# rpm -qa | grep png
libpng-1.2.2-16
libpng10-1.0.13-8

Any suggentions?

Try changing the makefile
gcc -Wall -O2 -s -o bwbar bwbar.c -lpng

Add -I/usr/include -I/usr/local/include
To form:

gcc -Wall -I/usr/include -I/usr/local/include -O2 -s -o bwbar bwbar.c -lpng

That might work.

Now I have update the libpng rpm to 1.2.2-16 and it outputs the following:


[root@trinisrv bwbar-1.2]# make
gcc -Wall -O2 -s -o bwbar bwbar.c -lpng
/usr/local/lib/libpng.so: undefined reference to `deflate'
/usr/local/lib/libpng.so: undefined reference to `inflate'
/usr/local/lib/libpng.so: undefined reference to `inflateInit_'
/usr/local/lib/libpng.so: undefined reference to `crc32'
/usr/local/lib/libpng.so: undefined reference to `pow'
/usr/local/lib/libpng.so: undefined reference to `deflateInit2_'
/usr/local/lib/libpng.so: undefined reference to `inflateReset'
/usr/local/lib/libpng.so: undefined reference to `deflateReset'
/usr/local/lib/libpng.so: undefined reference to `inflateEnd'
/usr/local/lib/libpng.so: undefined reference to `deflateEnd'
collect2: ld returned 1 exit status
make: *** [bwbar] Error 1

BTW, I tried chaning the makefile, but it doesn't make any difference at all.. Still the same output as above..

Instead of -lpng use:

-L/usr/lib -Wl,-rpath,/usr/lib -lpng12 -lz -lm

How I got to this is:

libpng-config --ldflags

You can alternativly use:

`libpng-config --ldflags` instead of -lpng12
When I'm too lazy to write a configure and I just make a makefile I use this. It executes the program and uses it's output. Note the ` encasing it.

Many many if not most libraries of this sort have this kind of program.
ls /usr/bin |grep config
To get a list of them, or just use the tab autocomplete to find them.
Seems that you don't need the cflags but for future refenrece you'd need

libpng-config --cflags and libpng-config --ldflags

The former is used when generating object files, .o files, that's the kind of error you had in the first place. The latter is for linking the kind of error you have now.

Wee! It works!

Thanks for the help.. Next time you visit Denmark come by and I'll buy you a beer! Or two.. ;D