text: #ifndef SG_LIB_H
  #define SG_LIB_H
  
  /*
   * Copyright (c) 2004-2013 Douglas Gilbert.
   * All rights reserved.
   * Use of this source code is governed by a BSD-style
   * license that can be found in the BSD_LICENSE file.
   */
  
  /*
   *
   * On 5th October 2004 a FreeBSD license was added to this file.
   * The intention is to keep this file and the related sg_lib.c file
   * as open source and encourage their unencumbered use.
   *
   * Current version number is in the sg_lib.c file and can be accessed
   * with the sg_lib_version() function.
   */
  
  
  /*
   * This header file contains defines and function declarations that may
   * be useful to applications that communicate with devices that use a
   * SCSI command set. These command sets have names like SPC-4, SBC-3,
   * SSC-3, SES-2 and draft standards defining them can be found at
   * http://www.t10.org . Virtually all devices in the Linux SCSI subsystem
   * utilize SCSI command sets. Many devices in other Linux device subsystems
   * utilize SCSI command sets either natively or via emulation (e.g. a
   * parallel ATA disk in a USB enclosure).
   */
  
  #include <stdio.h>
  #include <stdint.h>
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /* SCSI Peripheral Device Types (PDT) [5 bit field] */
  #define PDT_DISK 0x0    /* direct access block device (disk) */
  #define PDT_TAPE 0x1    /* sequential access device (magnetic tape) */
  #define PDT_PRINTER 0x2 /* printer device (see SSC-1) */
  #define PDT_PROCESSOR 0x3       /* processor device (e.g. SAFTE device) */
  #define PDT_WO 0x4      /* write once device (some optical disks) */
  #define PDT_MMC 0x5     /* CD/DVD/BD (multi-media) */
  #define PDT_SCANNER 0x6 /* obsolete */
  #define PDT_OPTICAL 0x7 /* optical memory device (some optical disks) */
  #define PDT_MCHANGER 0x8        /* media changer device (e.g. tape robot) */
  #define PDT_COMMS 0x9   /* communications device (obsolete) */
  #define PDT_SAC 0xc     /* storage array controller device */
  #define PDT_SES 0xd     /* SCSI Enclosure Services (SES) device */
  #define PDT_RBC 0xe     /* Reduced Block Commands (simplified PDT_DISK) */
  #define PDT_OCRW 0xf    /* optical card read/write device */
  #define PDT_BCC 0x10    /* bridge controller commands */
  #define PDT_OSD 0x11    /* Object Storage Device (OSD) */
  #define PDT_ADC 0x12    /* Automation/drive commands (ADC) */
  #define PDT_SMD 0x13    /* Security Manager Device (SMD) */
  #define PDT_WLUN 0x1e   /* Well known logical unit (WLUN) */
  #define PDT_UNKNOWN 0x1f        /* Unknown or no device type */
  
  #ifndef SAM_STAT_GOOD
  /* The SCSI status codes as found in SAM-4 at www.t10.org */
  #define SAM_STAT_GOOD 0x0
  #define SAM_STAT_CHECK_CONDITION 0x2
  #define SAM_STAT_CONDITION_MET 0x4
  #define SAM_STAT_BUSY 0x8
  #define SAM_STAT_INTERMEDIATE 0x10              /* obsolete in SAM-4 */
  #define SAM_STAT_INTERMEDIATE_CONDITION_MET 0x14  /* obsolete in SAM-4 */
  #define SAM_STAT_RESERVATION_CONFLICT 0x18
  #define SAM_STAT_COMMAND_TERMINATED 0x22        /* obsolete in SAM-3 */
  #define SAM_STAT_TASK_SET_FULL 0x28
  #define SAM_STAT_ACA_ACTIVE 0x30
  #define SAM_STAT_TASK_ABORTED 0x40
  #endif
  
  /* The SCSI sense key codes as found in SPC-4 at www.t10.org */
  #define SPC_SK_NO_SENSE 0x0
  #define SPC_SK_RECOVERED_ERROR 0x1
  #define SPC_SK_NOT_READY 0x2
  #define SPC_SK_MEDIUM_ERROR 0x3
  #define SPC_SK_HARDWARE_ERROR 0x4
  #define SPC_SK_ILLEGAL_REQUEST 0x5
  #define SPC_SK_UNIT_ATTENTION 0x6
  #define SPC_SK_DATA_PROTECT 0x7
  #define SPC_SK_BLANK_CHECK 0x8
  #define SPC_SK_COPY_ABORTED 0xa
  #define SPC_SK_ABORTED_COMMAND 0xb
  #define SPC_SK_VOLUME_OVERFLOW 0xd
  #define SPC_SK_MISCOMPARE 0xe
  #define SPC_SK_COMPLETED 0xf
  
  /* Transport protocol identifiers or just Protocol identifiers */
  #define TPROTO_FCP 0
  #define TPROTO_SPI 1
  #define TPROTO_SSA 2
  #define TPROTO_1394 3
  #define TPROTO_SRP 4
  #define TPROTO_ISCSI 5
  #define TPROTO_SAS 6
  #define TPROTO_ADT 7
  #define TPROTO_ATA 8
  #define TPROTO_UAS 9
  #define TPROTO_SOP 0xa
  #define TPROTO_NONE 0xf
  
  
  /* The format of the version string is like this: "1.47 20090201" */
  extern const char * sg_lib_version();
  
  /* Returns length of SCSI command given the opcode (first byte).
   * Yields the wrong answer for variable length commands (opcode=0x7f)
   * and potentially some vendor specific commands. */
  extern int sg_get_command_size(unsigned char cdb_byte0);
  
  /* Command name given pointer to the cdb. Certain command names
   * depend on peripheral type (give 0 if unknown). Places command
   * name into buff and will write no more than buff_len bytes. */
  extern void sg_get_command_name(const unsigned char * cdbp, int peri_type,
                                  int buff_len, char * buff);
  
  /* Command name given only the first byte (byte 0) of a cdb and
   * peripheral type. */
  extern void sg_get_opcode_name(unsigned char cdb_byte0, int peri_type,
                                 int buff_len, char * buff);
  
  /* Command name given opcode (byte 0), service action and peripheral type.
   * If no service action give 0, if unknown peripheral type give 0. */
  extern void sg_get_opcode_sa_name(unsigned char cdb_byte0, int service_action,
                                    int peri_type, int buff_len, char * buff);
  
  /* Fetch scsi status string. */
  extern void sg_get_scsi_status_str(int scsi_status, int buff_len, char * buff);
  
  /* This is a slightly stretched SCSI sense "descriptor" format header.
   * The addition is to allow the 0x70 and 0x71 response codes. The idea
   * is to place the salient data of both "fixed" and "descriptor" sense
   * format into one structure to ease application processing.
   * The original sense buffer should be kept around for those cases
   * in which more information is required (e.g. the LBA of a MEDIUM ERROR). */
  struct sg_scsi_sense_hdr {
      unsigned char response_code; /* permit: 0x0, 0x70, 0x71, 0x72, 0x73 */
      unsigned char sense_key;
      unsigned char asc;
      unsigned char ascq;
      unsigned char byte4;
      unsigned char byte5;
      unsigned char byte6;
      unsigned char additional_length;
  };
  
  /* Maps the salient data from a sense buffer which is in either fixed or
   * descriptor format into a structure mimicking a descriptor format
   * header (i.e. the first 8 bytes of sense descriptor format).
   * If zero response code returns 0. Otherwise returns 1 and if 'sshp' is
   * non-NULL then zero all fields and then set the appropriate fields in
   * that structure. sshp::additional_length is always 0 for response
   * codes 0x70 and 0x71 (fixed format). */
  extern int sg_scsi_normalize_sense(const unsigned char * sensep,
                                     int sense_len,
                                     struct sg_scsi_sense_hdr * sshp);
  
  /* Attempt to find the first SCSI sense data descriptor that matches the
   * given 'desc_type'. If found return pointer to start of sense data
   * descriptor; otherwise (including fixed format sense data) returns NULL. */
  extern const unsigned char * sg_scsi_sense_desc_find(
                  const unsigned char * sensep, int sense_len, int desc_type);
  
  /* Yield string associated with sense_key value. Returns 'buff'. */
  extern char * sg_get_sense_key_str(int sense_key, int buff_len, char * buff);
  
  /* Yield string associated with ASC/ASCQ values. Returns 'buff'. */
  extern char * sg_get_asc_ascq_str(int asc, int ascq, int buff_len,
                                    char * buff);
  
  /* Returns 1 if valid bit set, 0 if valid bit clear. Irrespective the
   * information field is written out via 'info_outp' (except when it is
   * NULL). Handles both fixed and descriptor sense formats. */
  extern int sg_get_sense_info_fld(const unsigned char * sensep, int sb_len,
                                   uint64_t * info_outp);
  
  /* Returns 1 if any of the 3 bits (i.e. FILEMARK, EOM or ILI) are set.
   * In descriptor format if the stream commands descriptor not found
   * then returns 0. Writes 1 or 0 corresponding to these bits to the
   * last three arguments if they are non-NULL. */
  extern int sg_get_sense_filemark_eom_ili(const unsigned char * sensep,
                                           int sb_len, int * filemark_p,
                                           int * eom_p, int * ili_p);
  
  /* Returns 1 if SKSV is set and sense key is NO_SENSE or NOT_READY. Also
   * returns 1 if progress indication sense data descriptor found. Places
   * progress field from sense data where progress_outp points. If progress
   * field is not available returns 0. Handles both fixed and descriptor
   * sense formats. N.B. App should multiply by 100 and divide by 65536
   * to get percentage completion from given value. */
  extern int sg_get_sense_progress_fld(const unsigned char * sensep,
                                       int sb_len, int * progress_outp);
  
  /* Closely related to sg_print_sense(). Puts decoded sense data in 'buff'.
   * Usually multiline with multiple '\n' including one trailing. If
   * 'raw_sinfo' set appends sense buffer in hex. */
  extern void sg_get_sense_str(const char * leadin,
                               const unsigned char * sense_buffer, int sb_len,
                               int raw_sinfo, int buff_len, char * buff);
  
  /* Yield string associated with peripheral device type (pdt). Returns
   * 'buff'. If 'pdt' out of range yields "bad pdt" string. */
  extern char * sg_get_pdt_str(int pdt, int buff_len, char * buff);
  
  /* Yield string associated with transport protocol identifier (tpi). Returns
   *    'buff'. If 'tpi' out of range yields "bad tpi" string. */
  extern char * sg_get_trans_proto_str(int tpi, int buff_len, char * buff);
  
  extern FILE * sg_warnings_strm;
  
  extern void sg_set_warnings_strm(FILE * warnings_strm);
  
  /* The following "print" functions send ACSII to 'sg_warnings_strm' file
   * descriptor (default value is stderr) */
  extern void sg_print_command(const unsigned char * command);
  extern void sg_print_sense(const char * leadin,
                             const unsigned char * sense_buffer, int sb_len,
                             int raw_info);
  extern void sg_print_scsi_status(int scsi_status);
  
  /* Utilities can use these process status values for syntax errors and
   * file (device node) problems (e.g. not found or permissions). */
  #define SG_LIB_SYNTAX_ERROR 1
  #define SG_LIB_FILE_ERROR 15
  
  /* The sg_err_category_sense() function returns one of the following.
   * These may be used as process status values (on exit). Notice that
   * some of the lower values correspond to SCSI sense key values. */
  #define SG_LIB_CAT_CLEAN 0      /* No errors or other information */
  /* Value 1 left unused for utilities to use SG_LIB_SYNTAX_ERROR */
  #define SG_LIB_CAT_NOT_READY 2  /* interpreted from sense buffer */
                                  /*       [sk,asc,ascq: 0x2,*,*] */
  #define SG_LIB_CAT_MEDIUM_HARD 3 /* medium or hardware error, blank check */
                                  /*       [sk,asc,ascq: 0x3/0x4/0x8,*,*] */
  #define SG_LIB_CAT_ILLEGAL_REQ 5 /* Illegal request (other than invalid */
                                  /* opcode):   [sk,asc,ascq: 0x5,*,*] */
  #define SG_LIB_CAT_UNIT_ATTENTION 6 /* interpreted from sense buffer */
                                  /*       [sk,asc,ascq: 0x6,*,*] */
          /* was SG_LIB_CAT_MEDIA_CHANGED earlier [sk,asc,ascq: 0x6,0x28,*] */
  #define SG_LIB_CAT_INVALID_OP 9 /* (Illegal request,) Invalid opcode: */
                                  /*       [sk,asc,ascq: 0x5,0x20,0x0] */
  #define SG_LIB_CAT_ABORTED_COMMAND 11 /* interpreted from sense buffer */
                                  /*       [sk,asc,ascq: 0xb,*,*] */
  #define SG_LIB_CAT_NO_SENSE 20  /* sense data with key of "no sense" */
                                  /*       [sk,asc,ascq: 0x0,*,*] */
  #define SG_LIB_CAT_RECOVERED 21 /* Successful command after recovered err */
                                  /*       [sk,asc,ascq: 0x1,*,*] */
  #define SG_LIB_CAT_MALFORMED 97 /* Response to SCSI command malformed */
  #define SG_LIB_CAT_SENSE 98     /* Something else is in the sense buffer */
  #define SG_LIB_CAT_OTHER 99     /* Some other error/warning has occurred */
                                  /* (e.g. a transport or driver error) */
  
  /* Returns a SG_LIB_CAT_* value. If cannot decode sense_buffer or a less
   * common sense key then return SG_LIB_CAT_SENSE .*/
  extern int sg_err_category_sense(const unsigned char * sense_buffer,
                                   int sb_len);
  
  /* Here are some additional sense data categories that are not returned
   * by sg_err_category_sense() but are returned by some related functions. */
  #define SG_LIB_CAT_ILLEGAL_REQ_WITH_INFO 17 /* Illegal request (other than */
                                  /* invalid opcode) plus 'info' field: */
                                  /*  [sk,asc,ascq: 0x5,*,*] */
  #define SG_LIB_CAT_MEDIUM_HARD_WITH_INFO 18 /* medium or hardware error */
                                  /* sense key plus 'info' field: */
                                  /*       [sk,asc,ascq: 0x3/0x4,*,*] */
  #define SG_LIB_CAT_TIMEOUT 33
  
  
  /* Iterates to next designation descriptor in the device identification
   * VPD page. The 'initial_desig_desc' should point to start of first
   * descriptor with 'page_len' being the number of valid bytes in that
   * and following descriptors. To start, 'off' should point to a negative
   * value, thereafter it should point to the value yielded by the previous
   * call. If 0 returned then 'initial_desig_desc + *off' should be a valid
   * descriptor; returns -1 if normal end condition and -2 for an abnormal
   * termination. Matches association, designator_type and/or code_set when
   * any of those values are greater than or equal to zero. */
  extern int sg_vpd_dev_id_iter(const unsigned char * initial_desig_desc,
                                int page_len, int * off, int m_assoc,
                                int m_desig_type, int m_code_set);
  
  
  /* <<< General purpose (i.e. not SCSI specific) utility functions >>> */
  
  /* Always returns valid string even if errnum is wild (or library problem).
   * If errnum is negative, flip its sign. */
  extern char * safe_strerror(int errnum);
  
  
  /* Print (to stdout) 'str' of bytes in hex, 16 bytes per line optionally
   * followed at the right hand side of the line with an ASCII interpretation.
   * Each line is prefixed with an address, starting at 0 for str[0]..str[15].
   * All output numbers are in hex. 'no_ascii' allows for 3 output types:
   *     > 0     each line has address then up to 16 ASCII-hex bytes
   *     = 0     in addition, the bytes are listed in ASCII to the right
   *     < 0     only the ASCII-hex bytes are listed (i.e. without address)
  */
  extern void dStrHex(const char* str, int len, int no_ascii);
  
  /* Returns 1 when executed on big endian machine; else returns 0.
   * Useful for displaying ATA identify words (which need swapping on a
   * big endian machine).
  */
  extern int sg_is_big_endian();
  
  /* Extract character sequence from ATA words as in the model string
   * in a IDENTIFY DEVICE response. Returns number of characters
   * written to 'ochars' before 0 character is found or 'num' words
   * are processed. */
  extern int sg_ata_get_chars(const unsigned short * word_arr, int start_word,
                              int num_words, int is_big_endian, char * ochars);
  
  /* Print (to stdout) 16 bit 'words' in hex, 8 words per line optionally
   * followed at the right hand side of the line with an ASCII interpretation
   * (pairs of ASCII characters in big endian order (upper first)).
   * Each line is prefixed with an address, starting at 0.
   * All output numbers are in hex. 'no_ascii' allows for 3 output types:
   *     > 0     each line has address then up to 8 ASCII-hex words
   *     = 0     in addition, the words are listed in ASCII pairs to the right
   *     = -1    only the ASCII-hex words are listed (i.e. without address)
   *     = -2    only the ASCII-hex words, formatted for "hdparm --Istdin"
   *     < -2    same as -1
   * If 'swapb' non-zero then bytes in each word swapped. Needs to be set
   * for ATA IDENTIFY DEVICE response on big-endian machines.
  */
  extern void dWordHex(const unsigned short* words, int num, int no_ascii,
                       int swapb);
  
  /* If the number in 'buf' can not be decoded or the multiplier is unknown
   * then -1 is returned. Accepts a hex prefix (0x or 0X) or a 'h' (or 'H')
   * suffix. Otherwise a decimal multiplier suffix may be given. Recognised
   * multipliers: c C  *1;  w W  *2; b  B *512;  k K KiB  *1,024;
   * KB  *1,000;  m M MiB  *1,048,576; MB *1,000,000; g G GiB *1,073,741,824;
   * GB *1,000,000,000 and <n>x<m> which multiplies <n> by <m> . */
  extern int sg_get_num(const char * buf);
  
  /* If the number in 'buf' can not be decoded then -1 is returned. Accepts a
   * hex prefix (0x or 0X) or a 'h' (or 'H') suffix; otherwise decimal is
   * assumed. Does not accept multipliers. Accept a comma (","), a whitespace
   * or newline as terminator.  */
  extern int sg_get_num_nomult(const char * buf);
  
  /* If the number in 'buf' can not be decoded or the multiplier is unknown
   * then -1LL is returned. Accepts a hex prefix (0x or 0X) or a 'h' (or 'H')
   * suffix. Otherwise a decimal multiplier suffix may be given. In addition
   * to supporting the multipliers of sg_get_num(), this function supports:
   * t T TiB  *(2**40); TB *(10**12); p P PiB  *(2**50); PB  *(10**15) . */
  extern int64_t sg_get_llnum(const char * buf);
  
  
  /* <<< Architectural support functions [is there a better place?] >>> */
  
  /* Non Unix OSes distinguish between text and binary files.
   * Set text mode on fd. Does nothing in Unix. Returns negative number on
   * failure. */
  extern int sg_set_text_mode(int fd);
  
  /* Set binary mode on fd. Does nothing in Unix. Returns negative number on
   * failure. */
  extern int sg_set_binary_mode(int fd);
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif
  