1.1. General

The Linux Standard Base (LSB) defines a system interface for compiled applications and a minimal environment for support of installation scripts. Its purpose is to enable a uniform industry standard environment for high-volume applications conforming to the LSB.

These specifications are composed of two basic parts: A common specification ("LSB-generic") describing those parts of the interface that remain constant across all implementations of the LSB, and an architecture-specific specification ("LSB-arch") describing the parts of the interface that vary by processor architecture. Together, the LSB-generic and the architecture-specific supplement for a single hardware architecture provide a complete interface specification for compiled application programs on systems that share a common hardware architecture.

The LSB-generic document shall be used in conjunction with an architecture-specific supplement. Whenever a section of the LSB-generic specification shall be supplemented by architecture-specific information, the LSB-generic document includes a reference to the architecture supplement. Architecture supplements may also contain additional information that is not referenced in the LSB-generic document.

The LSB contains both a set of Application Program Interfaces (APIs) and Application Binary Interfaces (ABIs). APIs may appear in the source code of portable applications, while the compiled binary of that application may use the larger set of ABIs. A conforming implementation shall provide all of the ABIs listed here. The compilation system may replace (e.g. by macro definition) certain APIs with calls to one or more of the underlying binary interfaces, and may insert calls to binary interfaces as needed.

The LSB is primarily a binary interface definition. Not all of the source level APIs available to applications may be contained in this specification.

1.2. Module Specific Scope

This is the Core module of the Linux Standards Base (LSB). This module provides the fundamental system interfaces, libraries, and runtime environment upon which all conforming applications and libraries depend.

Interfaces described in this module are mandatory except where explicitly listed otherwise. Core interfaces may be supplemented by other modules; all modules are built upon the core.

3.1. Relevant Libraries

The libraries listed in Table 3-1 shall be available on a Linux Standard Base system, with the specified runtime names. The libraries listed in Table 3-2 are architecture specific, but shall be available on all LSB conforming systems. This list may be supplemented or amended by the architecture-specific specification.

These libraries will be in an implementation-defined directory which the dynamic linker shall search by default.

3.2. LSB Implementation Conformance

A conforming implementation shall satisfy the following requirements:

• The implementation shall implement fully the architecture described in the hardware manual for the target processor architecture.

• The implementation shall be capable of executing compiled applications having the format and using the system interfaces described in this document.

• The implementation shall provide libraries containing the interfaces specified by this document, and shall provide a dynamic linking mechanism that allows these interfaces to be attached to applications at runtime. All the interfaces shall behave as specified in this document.

• The map of virtual memory provided by the implementation shall conform to the requirements of this document.

• The implementation's low-level behavior with respect to function call linkage, system traps, signals, and other such activities shall conform to the formats described in this document.

• The implementation shall provide all of the mandatory interfaces in their entirety.

• The implementation may provide one or more of the optional interfaces. Each optional interface that is provided shall be provided in its entirety. The product documentation shall state which optional interfaces are provided.

• The implementation shall provide all files and utilities specified as part of this document in the format defined here and in other referenced documents. All commands and utilities shall behave as required by this document. The implementation shall also provide all mandatory components of an application's runtime environment that are included or referenced in this document.

• The implementation, when provided with standard data formats and values at a named interface, shall provide the behavior defined for those values and data formats at that interface. However, a conforming implementation may consist of components which are separately packaged and/or sold. For example, a vendor of a conforming implementation might sell the hardware, operating system, and windowing system as separately packaged items.

• The implementation may provide additional interfaces with different names. It may also provide additional behavior corresponding to data values outside the standard ranges, for standard named interfaces.

3.3. LSB Application Conformance

A conforming application shall satisfy the following requirements:

• Its executable files are either shell scripts or object files in the format defined for the Object File Format system interface.

• Its object files participate in dynamic linking as defined in the Program Loading and Linking System interface.

• It employs only the instructions, traps, and other low-level facilities defined in the Low-Level System interface as being for use by applications.

• If it requires any optional interface defined in this document in order to be installed or to execute successfully, the requirement for that optional interface is stated in the application's documentation.

• It does not use any interface or data format that is not required to be provided by a conforming implementation, unless:

  • If such an interface or data format is supplied by another application through direct invocation of that application during execution, that application is in turn an LSB conforming application.

  • The use of that interface or data format, as well as its source, is identified in the documentation of the application.

• It shall not use any values for a named interface that are reserved for vendor extensions.

8.1. Introduction

An LSB-conforming implementation shall support the following base libraries which provide interfaces for accessing the operating system, processor and other hardware in the system.

• libc

• libm

• libgcc_s

• libdl

• libcrypt

• libpam

8.2. Program Interpreter

The Program Interpreter is specified in the appropriate architecture-specific LSB specification.

8.3. Interfaces for libc

Table 8-1 defines the library name and shared object name for the libc library

The behavior of the interfaces in this library is specified by the following specifications:

8.4. Data Definitions for libc

This section defines global identifiers and their values that are associated with interfaces contained in libc. These definitions are organized into groups that correspond to system headers. This convention is used as a convenience for the reader, and does not imply the existence of these headers, or their content.

These definitions are intended to supplement those provided in the referenced underlying specifications.

This specification uses ISO/IEC 9899 C Language as the reference programming language, and data definitions are specified in ISO C format. The C language is used here as a convenient notation. Using a C language description of these data objects does not preclude their use by other programming languages.

enum
{
  _ISupper, _ISlower, _ISalpha, _ISdigit, _ISxdigit, _ISspace, _ISprint,
    _ISgraph, _ISblank, _IScntrl, _ISpunct, _ISalnum
}
 ;

typedef struct __dirstream DIR;

struct dirent
{
  long int d_ino;
  off_t d_off;
  unsigned short d_reclen;
  unsigned char d_type;
  char d_name[256];
}
 ;
struct dirent64
{
  uint64_t d_ino;
  int64_t d_off;
  unsigned short d_reclen;
  unsigned char d_type;
  char d_name[256];
}
 ;

#define errno	(*__errno_location())

#define EPERM	1
#define ECHILD	10
#define ENETDOWN	100
#define ENETUNREACH	101
#define ENETRESET	102
#define ECONNABORTED	103
#define ECONNRESET	104
#define ENOBUFS	105
#define EISCONN	106
#define ENOTCONN	107
#define ESHUTDOWN	108
#define ETOOMANYREFS	109
#define EAGAIN	11
#define ETIMEDOUT	110
#define ECONNREFUSED	111
#define EHOSTDOWN	112
#define EHOSTUNREACH	113
#define EALREADY	114
#define EINPROGRESS	115
#define ESTALE	116
#define EUCLEAN	117
#define ENOTNAM	118
#define ENAVAIL	119
#define ENOMEM	12
#define EISNAM	120
#define EREMOTEIO	121
#define EDQUOT	122
#define ENOMEDIUM	123
#define EMEDIUMTYPE	124
#define ECANCELED	125
#define EACCES	13
#define EFAULT	14
#define ENOTBLK	15
#define EBUSY	16
#define EEXIST	17
#define EXDEV	18
#define ENODEV	19
#define ENOENT	2
#define ENOTDIR	20
#define EISDIR	21
#define EINVAL	22
#define ENFILE	23
#define EMFILE	24
#define ENOTTY	25
#define ETXTBSY	26
#define EFBIG	27
#define ENOSPC	28
#define ESPIPE	29
#define ESRCH	3
#define EROFS	30
#define EMLINK	31
#define EPIPE	32
#define EDOM	33
#define ERANGE	34
#define EDEADLK	35
#define ENAMETOOLONG	36
#define ENOLCK	37
#define ENOSYS	38
#define ENOTEMPTY	39
#define EINTR	4
#define ELOOP	40
#define ENOMSG	42
#define EIDRM	43
#define ECHRNG	44
#define EL2NSYNC	45
#define EL3HLT	46
#define EL3RST	47
#define ELNRNG	48
#define EUNATCH	49
#define EIO	5
#define ENOANO	55
#define EBADRQC	56
#define EBADSLT	57
#define EBFONT	59
#define ENXIO	6
#define ENOSTR	60
#define ENODATA	61
#define ETIME	62
#define ENOSR	63
#define ENONET	64
#define ENOPKG	65
#define EREMOTE	66
#define ENOLINK	67
#define EADV	68
#define ESRMNT	69
#define E2BIG	7
#define ECOMM	70
#define EPROTO	71
#define EMULTIHOP	72
#define EDOTDOT	73
#define EBADMSG	74
#define EOVERFLOW	75
#define ENOTUNIQ	76
#define EBADFD	77
#define EREMCHG	78
#define ELIBACC	79
#define ENOEXEC	8
#define ELIBBAD	80
#define ELIBSCN	81
#define ELIBMAX	82
#define ELIBEXEC	83
#define EILSEQ	84
#define ERESTART	85
#define ESTRPIPE	86
#define EUSERS	87
#define ENOTSOCK	88
#define EDEST