Unix |
Unix v6 |
|
perror(3) |
perror, syserrlist, sysnerr, errno system error messages
perror(s)
char *s; int sysnerr;
char *syserrlist[]; int errno;
produces a short error message describing the last error
encountered during a call to the system from a C program.
First the argument string is printed, then a colon, then the
message and a new-line. Most usefully, the argument string
is the name of the program which incurred the error. The
error number is taken from the external variable which is
set when errors occur but not cleared when non-erroneous
calls are made. To simplify variant formatting of messages,
the vector of message strings is provided; can be used as an
index in this table to get the message string without the
newline. is the largest message number provided for in the
table; it should be checked because new error codes may be
added to the system before they are added to the table.
Introduction to System Calls
perror(3) |