read_char, read_double, read_float, read_long, read_short -- read the next character, double, float, long or short value in binary representation from the input file.
A file pointer to a previously opened file. This may be either a file in the file system, or a string opened for read and write.
read_char returns the decimal representation of a string of length 1 containing a single character, or -1 indicating end of file.
read_double, read_float return a floating point value, or nan indicating end of file.
read_long, read_short return an integer value, or -1 indicating end of file.
These functions read the next character, double, float, long or short value in binary representation from the input file, regardless of Lisp expression syntax. This allows a programmer to read binary files constructed by other programs.
The file "myfile.dat" contains the following:
ajz
Successive calls to read_char will produce:
Gamma> ft = open ("myreadcfile.dat","r");
#<File:"myreadcfile.dat">
Gamma> read_char(ft);
97
Gamma> read_char(ft);
106
Gamma> read_char(ft);
122
Gamma> read_char(ft);
-1 Gamma>