cat << EOF > line.txt
0       0
1   1
2   0.5
4   2
2   1.5
EOF

gmt begin line_bezier pdf,png
gmt plot line.txt -R-0.25/4.25/-0.2/2.2 -JX3i/1.25i -W2p
gmt plot line.txt -Sc0.1i -Gred -Wfaint
gmt plot line.txt -W2p+s -X3i
gmt plot line.txt -Sc0.1i -Gred -Wfaint
rm line.txt
gmt end