libixp

git clone git://oldgit.suckless.org/libixp/
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error.c (2661B)

      1 /* Public Domain --Kris Maglione */
      2 #include <errno.h>
      3 #include <stdarg.h>
      4 #include <stdio.h>
      5 #include <stdlib.h>
      6 #include <string.h>
      7 #include "ixp_local.h"
      8 
      9 static int
     10 _vsnprint(char *buf, int nbuf, const char *fmt, va_list ap) {
     11 	return vsnprintf(buf, nbuf, fmt, ap);
     12 }
     13 
     14 static char*
     15 _vsmprint(const char *fmt, va_list ap) {
     16 	va_list al;
     17 	char *buf = "";
     18 	int n;
     19 
     20 	va_copy(al, ap);
     21 	n = vsnprintf(buf, 0, fmt, al);
     22 	va_end(al);
     23 
     24 	buf = malloc(++n);
     25 	if(buf)
     26 		vsnprintf(buf, n, fmt, ap);
     27 	return buf;
     28 }
     29 
     30 int (*ixp_vsnprint)(char*, int, const char*, va_list) = _vsnprint;
     31 char* (*ixp_vsmprint)(const char*, va_list) = _vsmprint;
     32 
     33 /* Approach to errno handling taken from Plan 9 Port. */
     34 enum {
     35 	EPLAN9 = 0x19283745,
     36 };
     37 
     38 /**
     39  * Function: ixp_errbuf
     40  * Function: ixp_errstr
     41  * Function: ixp_rerrstr
     42  * Function: ixp_werrstr
     43  * Variable: ixp_vsnprint
     44  *
     45  * Params:
     46  *	buf:  The buffer to read and/or fill.
     47  *	nbuf: The size of the buffer.
     48  *	fmt:  A format string with which to write the errstr.
     49  *	...:  Arguments to P<fmt>.
     50  *
     51  * These functions simulate Plan 9's errstr functionality.
     52  * They replace errno in libixp. Note that these functions
     53  * are not internationalized.
     54  *
     55  * F<ixp_errbuf> returns the errstr buffer for the current
     56  * thread. F<ixp_rerrstr> fills P<buf> with the data from
     57  * the current thread's error buffer, while F<ixp_errstr>
     58  * exchanges P<buf>'s contents with those of the current
     59  * thread's error buffer. F<ixp_werrstr> formats the given
     60  * format string, P<fmt>, via V<ixp_vsnprint> and writes it to
     61  * the error buffer.
     62  *
     63  * V<ixp_vsnprint> may be set to a function which will format
     64  * its arguments write the result to the P<nbuf> length buffer
     65  * V<buf>. The default value is F<vsnprintf>. The function must
     66  * format '%s' as a nul-terminated string and may not consume
     67  * any arguments not indicated by a %-prefixed format specifier,
     68  * but may otherwise behave in any manner chosen by the user.
     69  *
     70  * See also:
     71  *	V<ixp_vsmprint>
     72  */
     73 char*
     74 ixp_errbuf() {
     75 	char *errbuf;
     76 
     77 	errbuf = thread->errbuf();
     78 	if(errno == EINTR)
     79 		strncpy(errbuf, "interrupted", IXP_ERRMAX);
     80 	else if(errno != EPLAN9)
     81 		strncpy(errbuf, strerror(errno), IXP_ERRMAX);
     82 	return errbuf;
     83 }
     84 
     85 void
     86 errstr(char *buf, int nbuf) {
     87 	char tmp[IXP_ERRMAX];
     88 
     89 	strncpy(tmp, buf, sizeof tmp);
     90 	rerrstr(buf, nbuf);
     91 	strncpy(thread->errbuf(), tmp, IXP_ERRMAX);
     92 	errno = EPLAN9;
     93 }
     94 
     95 void
     96 rerrstr(char *buf, int nbuf) {
     97 	strncpy(buf, ixp_errbuf(), nbuf);
     98 }
     99 
    100 void
    101 werrstr(const char *fmt, ...) {
    102 	char tmp[IXP_ERRMAX];
    103 	va_list ap;
    104 
    105 	va_start(ap, fmt);
    106 	ixp_vsnprint(tmp, sizeof tmp, fmt, ap);
    107 	va_end(ap);
    108 	strncpy(thread->errbuf(), tmp, IXP_ERRMAX);
    109 	errno = EPLAN9;
    110 }
    111