This section summarizes the synatx of survex datafile. See [1] for more details.

Survex datafiles are text files with command lines and data lines. A command line begins with a keyword, a word which starts with an asterisk "*". The data lines contain the survey data. Comments are supported. A comment begins with a semicolon, ';', and goes to the end of the line. Furthermore extra data on a data line are ignored.

Station names are referred in a namespace in which the left entry is the most general, and the right entry is the name of the station. For example, lost_cave.main_passage.14 is the full name of the station "14" in the survey "main_passage" of the cave "lost_cave".

A survex datafile starts with a "*begin <survey_name>" command and ends with a "*end <survey_name>" command. Both commands take the name of the survey, which must be the same.

Here are some survex commands.

• *data. It specifies the order of the survey data on the data lines that follow. For example, *data normal from to length clino compass states that the data have normal style, and you have to insert the survey data in the following order: from_station, to_station, distance, inclination, and compass measurements. A data line following this command might look like 1 2 4.30 17 217: this is the shot 1-2 of 4.3 meters, 17°of inclination, and 217°north
• *entrance states that a station is an entrance. For example *entrance 1 states that station "1" is a cave entrance.
• *equate defines the equivalence of two stations (possibly from different surveys). For example *equate 1 main_passage.14 defines that the station "14" of the survey "main_passages" coincides with the station "1" of the current survey.
• *include is used to include other survex datafiles. For example "*include main_passage.svx" includes the survex data file main_passage.sxv.
• *export lists the stations referable from other surveys. For example, survey "main_passage" should have the command "*export 14" to make the station "14" referable in an "*equate" command of other surveys. Or the global datafile can have the command "*export main_passage.14" before (or after?) including the datafile of the survey "main_passage".
• *fix specifies the geographical coordinates of a station. For example "*fix 1 ..." TODO
• *units specifies the units used for a measure. For example, *units length 0.01 meter states that lengths are expressed in units of centimeters (0.01 m). Another example: *units compass grad states that compass readings are in centesimal degrees.
• *team specifies the name of a survey team member, and optionally his/her roles. For example. "*team xyz compass clino" states that "xyz" was at the compass and clino readings.

Here is a simple example, the first survey file of the sample cave used in these chapter. Only the first few data lines have been included. Notice the "*export" command, that makes the station "24" available to join with other surveys.

*begin gm-01
*export 24
*data normal from to tape compass clino ignoreall
*units length metres
*calibrate tape 0.0
*units compass degrees
*calibrate compass 0.0
*units clino degrees
*calibrate clino 0.0
;end generated presettings

*units length metres
*title "Grazie Mille"
*team "L. Aimar" compass clino
*team "A. Premazzi" notes pictures
*team "S. Vandone" tape
*team "A. Venturini" tape

; Cap 1 = ingresso
*entrance 1

*data normal from to length clino compass
1 2    5.70   -52   190
2 3    6.50   -50   205
3 4    2.80   -90     0
4 5    3.65   -50   193
5 6    4.35   -33   228
...

*end gm-01

Here is the global survex file that includes the three survey files and joins the surveys with "*equate" commands:

*begin gm

*data normal from to tape compass clino ignoreall
*units length metres
*calibrate tape 0.0
*units compass degrees
*calibrate compass 0.0
*units clino degrees
*calibrate clino 0.0
;end generated presettings

*equate gm-01.24 gm-02.1
*equate gm-02.13 gm.03.1

*include gm-01/gm-01.svx
*include gm-02/gm-02.svx
*include gm-03/gm-03.svx

*end gm