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)