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UNIX for Dummies Questions & Answers
UNIX basics
Post 302920668 by DGPickett on Friday 10th of October 2014 05:23:54 PM
10-10-2014
A Parameter is an Argument with a stuck up attitude? An Argument is a Parameter with a bad attitude? 
Yes, UNIX is an O/S, the variables and such come with languages, applications, the O/S kernel and libraries. UNIX is mostly written in C, or these days maybe C++, and comes with libraries that are most accessible in those languages. Other languages wrote interfaces to them. Since libraries are in execution or object code, any language can link to them and pass and receive data, sometimes with other real world side effects like writing a file.
The shell is a slightly more human friendly, interactive- and interpretation-oriented language. There are many variations on the shell.
Variables exist in the memory space of the application's process and in the UNIX kernel. They usually conform to datatypes of the common languages and CPU hardware, like the 4 byte or 32 bit 2's complement big-endian signed binary integer, or int. All memory and file space is alike until a context is thrown over it. If it is string or character data, still the glyphs you see when it is prints and the amount of space it takes is context-dependent: ASCII, EBCDIC, UNICODE, UTF-8, EUC, Latin-1, iso8859-1, . . . . Memory can have code and variables in it, as well as unallocated spaces. For a compiler or link loader, the code is also just data out of context. Most code is CPU-specific and somewhat O/S specific (object code), but some is for an interpreter like the shell (scripts or *codes) or to instruct a compiler (source code). Source code is text from humans that is compiled into object code for execution. Some programs can be executed directly, and others are just libraries of callable subroutines and other constants to assist runnable programs and each other. The UNIX kernel is the first loaded program at the bottom of memory by bootload, which serves all the running processes, some of which are part of the UNIX O/S.
Knowing the big picture keeps the snow level down. Everything runs on top of this, one way or the other. Every O/S is many ways similar.
Yes, UNIX is an O/S, the variables and such come with languages, applications, the O/S kernel and libraries. UNIX is mostly written in C, or these days maybe C++, and comes with libraries that are most accessible in those languages. Other languages wrote interfaces to them. Since libraries are in execution or object code, any language can link to them and pass and receive data, sometimes with other real world side effects like writing a file.
The shell is a slightly more human friendly, interactive- and interpretation-oriented language. There are many variations on the shell.
Variables exist in the memory space of the application's process and in the UNIX kernel. They usually conform to datatypes of the common languages and CPU hardware, like the 4 byte or 32 bit 2's complement big-endian signed binary integer, or int. All memory and file space is alike until a context is thrown over it. If it is string or character data, still the glyphs you see when it is prints and the amount of space it takes is context-dependent: ASCII, EBCDIC, UNICODE, UTF-8, EUC, Latin-1, iso8859-1, . . . . Memory can have code and variables in it, as well as unallocated spaces. For a compiler or link loader, the code is also just data out of context. Most code is CPU-specific and somewhat O/S specific (object code), but some is for an interpreter like the shell (scripts or *codes) or to instruct a compiler (source code). Source code is text from humans that is compiled into object code for execution. Some programs can be executed directly, and others are just libraries of callable subroutines and other constants to assist runnable programs and each other. The UNIX kernel is the first loaded program at the bottom of memory by bootload, which serves all the running processes, some of which are part of the UNIX O/S.
Knowing the big picture keeps the snow level down. Everything runs on top of this, one way or the other. Every O/S is many ways similar.
Last edited by DGPickett; 10-10-2014 at 06:31 PM..
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LEARN ABOUT REDHAT
sane-ricoh
sane-ricoh(5) File Formats Manual sane-ricoh(5) NAME
sane-ricoh - SANE backend for Ricoh flatbed scanners DESCRIPTION
The sane-ricoh library implements a SANE (Scanner Access Now Easy) backend that provides access to the following Ricoh flatbed scanners: IS50 IS60 DEVICE NAMES
This backend expects device names of the form: special Where special is the path-name for the special device that corresponds to a SCSI scanner. The special device name must be a generic SCSI device or a symlink to such a device. The program sane-find-scanner helps to find out the correct device. Under Linux, such a device name could be /dev/sga or /dev/sge, for example. See sane-scsi(5) for details. FILES
/etc/sane.d/ricoh.conf The backend configuration file (see also description of SANE_CONFIG_DIR below). /usr/lib/sane/libsane-ricoh.a The static library implementing this backend. /usr/lib/sane/libsane-ricoh.so The shared library implementing this backend (present on systems that support dynamic loading). ENVIRONMENT
SANE_CONFIG_DIR This environment variable specifies the list of directories that may contain the configuration file. Under UNIX, the directories are separated by a colon (`:'), under OS/2, they are separated by a semi-colon (`;'). If this variable is not set, the configura- tion file is searched in two default directories: first, the current working directory (".") and then in /etc/sane.d. If the value of the environment variable ends with the directory separator character, then the default directories are searched after the explic- itly specified directories. For example, setting SANE_CONFIG_DIR to "/tmp/config:" would result in directories "tmp/config", ".", and "/etc/sane.d" being searched (in this order). SANE_DEBUG_RICOH If the library was compiled with debug support enabled, this environment variable controls the debug level for this backend. Higher debug levels increase the verbosity of the output. Example: export SANE_DEBUG_RICOH=4 SEE ALSO
sane(7), sane-scsi(5) AUTHOR
Feico W. Dillema 24 Jun 2000 sane-ricoh(5)