I have this shell script:
#!/bin/sh
r.mapcalc water = 120
d.rast water
i=1
while [ $i != 100 ]
do
n=1
while [ $n != 10 ]
do
r.mapcalc < water.mapcalc
d.rast water
n='expr $n + 1'
done
g.copy rast=water,water.$i
i = 'expr $i + 1'
done
It is from http://grass.osgeo.org/gdp/raster/mapcalc-algebra.pdf. I understand the syntax of the code since I am a programmer, but I cannot understand the line r.mapcalc < water.mapcalc. What does it mean? Sorry first time to use a shell script.
