5.1.105 read

Syntax:

read ( link_expression )
for DBM links:
read ( link_expression )
read ( link_expression, string_expression )

Type:

any

Purpose:

reads data from a link.
For ASCII links, the content of the entire file is returned as one string. If the ASCII link is the empty string, read reads from standard input.
For MP links, one expression is read from the link and returned after evaluation.
For MPtcp links the read command blocks as long as there is no data to be read from the link. The status command can be used to check whether or not there is data to be read.
For DBM links, a read with one argument returns the value of the next entry in the data base, and a read with two arguments returns the value to the key given as the second argument from the data base.

Example:

ring r=32003,(x,y,z),dp; ideal i=x+y,z3+22y; // write the ideal i to the file save_i write(":w save_i",i); ring r0=0,(x,y,z),Dp; // create an ideal k equal to the content // of the file save_i string s="ideal k="+read("save_i")+";"; execute(s); k; → k[1]=x+y → k[2]=z3+22y

See execute; getdump; link; status; write.