NAME

       xgetaline, xfseek, xfopen, xfclose, getaline, fassert - file manipulation utilities

SYNOPSIS

       #include <files.h>

       FILE *xfopen(const char *filename, const char *mode);
       void xfclose(FILE *fp);
       void xfseek(FILE *fp, long offset, int origin);
       char *getaline(FILE *fp);
       char *xgetaline(FILE *fp);
       void fassert(FILE *fp);

DESCRIPTION

       These  functions  are  useful  for  file  manipulation.   The  functions  that begin with x work like the
       functions without the letter, except if there is an error, they print  an  error  message  and  kill  the
       program.

       getaline  reads  a  line  from  the given file.  It allocates the memory for the line with malloc(3), and
       returns a pointer to the beginning of the line.  If there is an error, it returns NULL.  If the  returned
       value is not NULL, the caller is responsible for freeing the memory.  The newline is removed from the end
       of the line.

       fassert checks that the argument is not NULL, and that (for a non-NULL argument) the file does  not  have
       its error indicator flag set.  If either condition is true, it prints an error message and termiantes the
       program.   If neither condition is true, it does nothing.  This can be used to add checks that the I/O in
       a  program  is  going  well;  however,  it is mostly useful only for small programs, because more serious
       programs need to handle the errors more gracefully.

SEE ALSO

       publib(3)

AUTHOR

       Lars Wirzenius (lars.wirzenius@helsinki.fi)