From 78e51a8c6678b6e3dff3d619aa786669f531f4bc Mon Sep 17 00:00:00 2001 From: rsc Date: Fri, 14 Jan 2005 03:45:44 +0000 Subject: checkpoint --- man/man3/errstr.html | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 man/man3/errstr.html (limited to 'man/man3/errstr.html') diff --git a/man/man3/errstr.html b/man/man3/errstr.html new file mode 100644 index 00000000..547efc8d --- /dev/null +++ b/man/man3/errstr.html @@ -0,0 +1,121 @@ + +errstr(3) - Plan 9 from User Space + + + + +
+
+
ERRSTR(3)ERRSTR(3) +
+
+

NAME
+ +
+ + errstr, rerrstr, werrstr – description of last system call error
+ +
+

SYNOPSIS
+ +
+ + #include <u.h>
+ #include <libc.h> +
+ + int errstr(char *err, uint nerr) +
+ + void rerrstr(char *err, uint nerr) +
+ + void werrstr(char *fmt, ...)
+ +
+

DESCRIPTION
+ +
+ + When a system call fails it returns –1 and records a null terminated + string describing the error in a per-process buffer. Errstr swaps + the contents of that buffer with the contents of the array err. + Errstr will write at most nerr bytes into err; if the per-process + error string does not fit, it is silently truncated at a UTF + character boundary. The returned string is NUL-terminated. Usually + errstr will be called with an empty string, but the exchange property + provides a mechanism for libraries to set the return value for + the next call to errstr. +
+ + The per-process buffer is ERRMAX bytes long. Any error string + provided by the user will be truncated at ERRMAX−1 bytes. ERRMAX + is defined in <libc.h>. +
+ + If no system call has generated an error since the last call to + errstr with an empty string, the result is an empty string. +
+ + The verb r in print(3) calls errstr and outputs the error string. + +
+ + Rerrstr reads the error string but does not modify the per-process + buffer, so a subsequent errstr will recover the same string. +
+ + Werrstr takes a print style format as its argument and uses it + to format a string to pass to errstr. The string returned from + errstr is discarded. +
+ + The error string is maintained in parallel with the Unix error + number errno. Changing errno will reset the error string, and + changing the error string via errstr or werrstr will reset errno.
+ +
+

SOURCE
+ +
+ + /usr/local/plan9/src/lib9/errstr.c
+ +
+

DIAGNOSTICS
+ +
+ + Errstr always returns 0.
+ +
+

SEE ALSO
+ +
+ + intro(3), perror(3)
+ +
+

BUGS
+ +
+ + The implementation sets errno to the (somewhat arbitrary) constant + 0x19283745 when the error string is valid. When errno is set to + other values, the error string is synthesized using strerror(3).
+ +
+ +

 +
+
+ + +
+
+
+Space Glenda +
+
+ + -- cgit v1.2.3