ms_readmsr.3

.TH MS_READMSR 3 2011/01/06 "Libmseed API"
.SH NAME
ms_readmsr - Read Mini-SEED data from files

.SH SYNOPSIS
.nf
.B #include <libmseed.h>

.BI "int \fBms_readmsr\fP ( MSRecord **ppmsr, char *" msfile ", int " reclen ","
.BI "                 off_t *" fpos ", int *" last ", flag " skipnotdata ","
.BI "                 flag " dataflag ",flag " verbose " );"

.BI "int \fBms_readmsr_r\fP ( MSFileParam **ppmsfp, MSRecord **ppmsr, char *" msfile ","
.BI "                    int " reclen ", off_t *" fpos ", int *" last ","
.BI "                    flag " skipnotdata ", flag " dataflag ",flag " verbose " );"

.BI "int \fBms_readtraces\fP ( MSTraceGroup **ppmstg, char *" msfile ", int " reclen ", "
.BI "                    double " timetol ", double " sampratetol ","
.BI "                    flag " dataquality ", flag " skipnotdata ","
.BI "                    flag " dataflag ", flag " verbose " );"

.BI "int \fBms_readtraces_timewin\fP ( MSTraceGroup **ppmstg, char *" msfile ","
.BI "                    int " reclen ",  double " timetol ", double " sampratetol ","
.BI "                    hptime_t " starttime ", hptime_t " endtime ","
.BI "                    flag " dataquality ", flag " skipnotdata ","
.BI "                    flag " dataflag ", flag " verbose " );"

.BI "int \fBms_readtraces_selection\fP ( MSTraceGroup **ppmstg, char *" msfile ","
.BI "                    int " reclen ",  double " timetol ", double " sampratetol ","
.BI "                    Selections *" selections ", flag " dataquality ","
.BI "                    flag " skipnotdata ", flag " dataflag ", flag " verbose " );"

.BI "int \fBms_readtracelist\fP ( MSTraceList **ppmstl, char *" msfile ", int " reclen ","
.BI "                       double " timetol ", double " sampratetol ","
.BI "                       flag " dataquality ", flag " skipnotdata ","
.BI "                       flag " dataflag ", flag " verbose " );"

.BI "int \fBms_readtracelist_timewin\fP ( MSTraceList **ppmstl, char *" msfile ","
.BI "                       int " reclen ", double " timetol ", double " sampratetol ","
.BI "                       hptime_t " starttime ", hptime_t " endtime ","
.BI "                       flag " dataquality ", flag " skipnotdata ","
.BI "                       flag " dataflag ", flag " verbose " );"

.BI "int \fBms_readtracelist_selection\fP ( MSTraceList **ppmstl, char *" msfile ","
.BI "                       int " reclen ", double " timetol ", double " sampratetol ","
.BI "                       Selections *" selections ", flag " dataquality ","
.BI "                       flag " skipnotdata ", flag " dataflag ", flag " verbose " );"
.fi

.SH DESCRIPTION
Both \fBms_readmsr\fP and \fBms_readmsr_r\fP will open and read, with
subsequent calls, all Mini-SEED records from a specified file.
Standard input will be opened if \fImsfile\fP is "-" (dash).  As each
record is read it is unpacked using \fBmsr_unpack(3)\fP.  If the
MSRecord struct at \fI*ppmsr\fP has not been initialized it must be
set to NULL and it will be initialize it automatically.

The \fBms_readmsr\fP version is not thread safe.  The reentrant
\fBms_readmsr_r\fP version is thread safe and can be used to read more
than one file in parallel.  \fBms_readmsr_r\fP stores all static file
reading parameters in a MSFileParam struct.  A pointer to this struct
must be supplied by the caller (\fIppmsfp\fP), memory will be
allocated on the initial call if the pointer is NULL.

If \fIreclen\fP is 0 or negative the length of every record is
automatically detected.  For auto length detection records are first
searched for a Blockette 1000 and if none is found a search is
conducted for the next valid record header (the existence of the next
record or end-of-file implying the length of the current record).

If the \fIfpos\fP pointer is not NULL the value will be set to the
file position (offset from the beginning in bytes) from where the
returned record was read.  As a special case, if \fIfpos\fP is not
NULL and the value it points to is less than zero it will be
interpreted as the (positive) offset in the file at which to begin
reading data; this feature does not work with packed files.

If the \fIlast\fP pointer is not NULL the value will be set to 1 when
the record at the end of the file is being returned, otherwise it will
be 0.  This indicator will not be set when the last valid record in
the file is followed by padding.

If the \fIskipnotdata\fP flag is true (not 0) any data chunks read
that do not have valid data record indicators (i.e. D, R, or Q) will
be skipped.

The \fIdataflag\fP argument is passed directly to \fBmsr_unpack(3)\fP
and controls whether data samples are unpacked.

After reading all the input records the controlling program should
call it one last time with \fImsfile\fP set to NULL.  This will close
the file and cleanup allocated memory.

If \fBms_readmsr\fP or \fBms_readmsr_r\fP are called with a different
file than the one they currently have open they will close the
currently open file, open the new file and print an error message.
Properly coded applications should reset the function when the end of
file has been reached as described above and not rely on this
behavior.

The \fBms_readtraces\fP and \fBms_readtracelist\fP routines read all
Mini-SEED records from a file using \fBms_readmsr_r\fP and adds each
one to either a MSTraceGroup or MSTraceList using
\fBmst_addmsrtogroup(3)\fP and \fBmstl_addmsr(3)\fP respectively.  The
\fImsfile\fP, \fIreclen\fP, \fIskipnotdata\fP and \fIdataflag\fP
arguments are passed directly to \fBms_readmsr_r\fP.  The
\fItimetol\fP, \fIsampratetol\fP and \fIdataquality\fP arguments are
passed directly to \fBmst_addmsrtogroup(3)\fP or \fBmstl_addmsr(3)\fP.
If the pointer to the MSTraceGroup or MSTraceList struct has not been
initialized it must be set to NULL and it will be initialize
automatically.  The MSTraceGroup or MSTraceList structures may already
contain entries and will be added to by these routines.  These
routines are thread safe.

The \fBms_readtraces_timewin\fP and \fBms_readtracelist_timewin\fP
routines perform the same function as \fBms_readtraces\fP and
\fBms_readtracelist\fP but will limit the data to records containing
samples between the specified \fIstarttime\fP and \fIendtime\fP.

The \fBms_readtraces_selection\fP and \fBms_readtracelist_selection\fP
routines perform the same function as \fBms_readtraces\fP and
\fBms_readtracelist\fP but will limit the data to records that match
the specified \fIselections\fP.  Selections include criteria for
source name and time window parameters, see \fBms_selection(3)\fP for
more information.

.SH RETURN VALUES
On the sucessful read and parsing of a record \fBms_readmsr\fP and
\fBms_readmsr_r\fP return MS_NOERROR and populate the MSRecord struct
at \fI*ppmsr\fP.  Upon reaching the end of the input file these
routines return MS_ENDOFFILE.  On error these routines return a
libmseed error code (defined in libmseed.h)

On the sucessful read and parsing of a file \fBms_readtraces\fP and
\fBms_readtracelist\fP return MS_NOERROR and populate the MSTraceGroup
or MSTraceList struct.  On error these routines return a libmseed
error code (defined in libmseed.h)

.SH PACKED FILES
\fBms_readmsr\fP, \fBms_readtraces\fP and \fBms_readtracelist\fP will
read packed Mini-SEED files.  Packed Mini-SEED is the indexed archive
format used internally at the IRIS Data Management Center and probably
not used anywhere else.

.SH EXAMPLE
Skeleton code for reading a file with \fBms_readmsr(3)\fP:

.nf
main() {
  MSRecord *msr = NULL;
  int retcode;

  while ( (retcode = ms_readmsr (&msr, filename, 0, NULL, NULL, 1, 0, verbose)) == MS_NOERROR )
    {
       /* Do something with the record here, e.g. print */
       msr_print (msr, verbose);
    }

  if ( retcode != MS_ENDOFFILE )
    ms_log (2, "Error reading input file %s: %s\\n", filename, ms_errorstr(retcode));

  /* Cleanup memory and close file */
  ms_readmsr (&msr, NULL, 0, NULL, NULL, 0, 0, verbose);
}

For reading a file with the thread safe \fBms_readmsr_r(3)\fP:

.nf
main() {
  MSRecord *msr = NULL;
  MSFileParam *msfp = NULL;
  int retcode;

  while ( (retcode = ms_readmsr_r (&msfp, &msr, filename, 0, NULL, NULL, 1, 0, verbose)) == MS_NOERROR )
    {
       /* Do something with the record here, e.g. print */
       msr_print (msr, verbose);
    }

  if ( retcode != MS_ENDOFFILE )
    ms_log (2, "Error reading input file %s: %s\\n", filename, ms_errorstr(retcode));

  /* Cleanup memory and close file */
  ms_readmsr_r (&msfp, &msr, NULL, 0, NULL, NULL, 0, 0, verbose);
}

.fi
For reading a file with \fBms_readtraces(3)\fP:
.nf

main() {
  MSTraceList *mstl = NULL;
  int retcode;

  retcode = ms_readtracelist (&mstl, filename, 0, -1.0, -1.0, 0, 1, 0, verbose);

  if ( retcode != MS_NOERROR )
    ms_log (2, "Error reading input file %s: %s\\n", filename, ms_errorstr(retcode));

  retcode = ms_readtracelist (&mstl, filename2, 0, -1.0, -1.0, 0, 1, 0, verbose);

  if ( retcode != MS_NOERROR )
    ms_log (2, "Error reading input file %s: %s\\n", filename2, ms_errorstr(retcode));

  if ( ! mstl )
    {
      ms_log (2, "Error reading file\\n");
      return -1;
    }

  /* Do something with the traces here, e.g. print */
  mstl_printtracelist (mstl, 0, verbose, 0);

  mstl_free (&mstl);
}
.fi

.SH SEE ALSO
\fBms_intro(3)\fP, \fBmsr_unpack(3)\fP, \fBmst_addmsrtogroup(3)\fP,
\fBmstl_addmsr(3)\fP, \fBms_log(3)\fP and \fBms_errorstr(3)\fP.

.SH AUTHOR
.nf
Chad Trabant
IRIS Data Management Center
.fi