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Added the _printf() interface. (CVS 150) 

FossilOrigin-Name: f9372072a6d6caa15fa14ec722523944470fe155
This commit is contained in:
drh 2000-10-08 22:20:57 +00:00
parent 35d5d9e212
commit a18c5681e9
10 changed files with 1167 additions and 74 deletions
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6
Makefile.in
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@ -48,7 +48,7 @@ LIBREADLINE = @TARGET_READLINE_LIBS@
# Object files for the SQLite library.
#
LIBOBJ = build.o dbbe.o delete.o expr.o insert.o \
main.o parse.o select.o table.o tokenize.o update.o \
main.o parse.o printf.o select.o table.o tokenize.o update.o \
util.o vdbe.o where.o tclsqlite.o
# All of the source code files.
@ -62,6 +62,7 @@ SRC = \
$(TOP)/src/insert.c \
$(TOP)/src/main.c \
$(TOP)/src/parse.y \
$(TOP)/src/printf.c \
$(TOP)/src/select.c \
$(TOP)/src/shell.c \
$(TOP)/src/sqlite.h.in \
@ -164,6 +165,9 @@ update.o: $(TOP)/src/update.c $(HDR)
tclsqlite.o: $(TOP)/src/tclsqlite.c $(HDR)
$(TCC) $(GDBM_FLAGS) $(TCL_FLAGS) -c $(TOP)/src/tclsqlite.c
printf.o: $(TOP)/src/printf.c $(HDR)
$(TCC) $(GDBM_FLAGS) $(TCL_FLAGS) -c $(TOP)/src/printf.c
gdbmdump: $(TOP)/tool/gdbmdump.c
$(TCC) $(GDBM_FLAGS) -o gdbmdump $(TOP)/tool/gdbmdump.c $(LIBGDBM)

2
VERSION
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@ -1 +1 @@
1.0.8
1.0.9

25
manifest
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@ -1,9 +1,9 @@
C Version\s1.0.8\s(CVS\s494)
D 2000-09-30T23:00:00
C Added\sthe\s_printf()\sinterface.\s(CVS\s150)
D 2000-10-08T22:20:57
F COPYRIGHT 74a8a6531a42e124df07ab5599aad63870fa0bd4
F Makefile.in 2fe404a488607712e569d69974d7929bae06ad1e
F Makefile.in f0b70aaa6717f9454c787dc74e5504c98ae7ea18
F README 51f6a4e7408b34afa5bc1c0485f61b6a4efb6958
F VERSION c2e64b60cb74d152b5b5a0822f0e8cb673c928da
F VERSION 1fe894c9b80001e9dbc3b40ef1f4f984c9b624f3
F configure 3dc1edb9dcf60215e31ff72b447935ab62211442 x
F configure.in d892ca33db7e88a055519ce2f36dcb11020e8fff
F doc/lemon.html e233a3e97a779c7a87e1bc4528c664a58e49dd47
@ -15,10 +15,11 @@ F src/expr.c e8e350d7baa33bd9ed8701c159eaba5e912e0adb
F src/insert.c f146f149ad2422a1dc3bfa7a1651a25940f98958
F src/main.c 9a89579b40e498920f86e89878f52185457b9c2c
F src/parse.y 5d199034de5d29ebedb42c1c51f34db4df40cbe5
F src/printf.c 534954b942046761e0860c30a9031fa9d803ca3c
F src/select.c d382e96c2221d08367cc87976f2b574537c9de97
F src/shell.c 3d25f6709c2794cd910733a48a14f105eed6d7f3
F src/shell.c ef5d12129c824cb98238763e9e86ca1847e0c7bd
F src/shell.tcl 27ecbd63dd88396ad16d81ab44f73e6c0ea9d20e
F src/sqlite.h.in 1e0e4495172f752935ad534871ff726ae509d2f0
F src/sqlite.h.in 8d87c93de1b43c3cce984a4204d8de84e0a626b6
F src/sqliteInt.h b65fdecac7281aafb4c9ff3e79ea1b5546478385
F src/table.c 12f0165b47178b54a675d25ed373ee7e798d6ff0
F src/tclsqlite.c 7ccccae67fb36ed60ec98282953bf5dad0f9c16f
@ -62,8 +63,8 @@ F tool/renumberOps.awk 6d067177ad5f8d711b79577b462da9b3634bd0a9
F www/arch.fig 4f246003b7da23bd63b8b0af0618afb4ee3055c8
F www/arch.png 8dae0766d42ed3de9ed013c1341a5792bcf633e6
F www/arch.tcl a40380c1fe0080c43e6cc5c20ed70731511b06be
F www/c_interface.tcl 73b5c1354e250a12ceaaccc376611351c867146a
F www/changes.tcl d62039b5387cc0871ec1bd3b15065a7c7d421cb1
F www/c_interface.tcl 47d6b9b66510be10d3b482ce978a317a183477e5
F www/changes.tcl c4f4584325dd55f7f4146bb9f5c5f9f7ce385302
F www/crosscompile.tcl 19734ce7f18b16ff2ed8479412abf8aca56e1dcc
F www/fileformat.tcl cfb7fba80b7275555281ba2f256c00734bcdd1c9
F www/index.tcl b19418d506f90968deef972bf1b427d98bdf13e0
@ -71,9 +72,9 @@ F www/lang.tcl 9192e114b19987e630a41e879585b87006eb84a1
F www/mingw.tcl fc5f4ba9d336b6e8c97347cc6496d6162461ef60
F www/opcode.tcl cb3a1abf8b7b9be9f3a228d097d6bf8b742c2b6f
F www/sqlite.tcl cb0d23d8f061a80543928755ec7775da6e4f362f
F www/tclsqlite.tcl 21ecd82eaea3ce3d08593a9a2d2bfdb3c1f7b547
F www/tclsqlite.tcl ae101d5f7c07dcc59770e2a84aae09025fab2dad
F www/vdbe.tcl bcbfc33bcdd0ebad95eab31286adb9e1bc289520
P 7e0bacedf928095b29e7166eacd2356e8169d6dd
R 3e751dc5aea8f130e00211562c95fd7d
P 384909e50f4ae2e84534f9a6505cfb5cc9f4d6ca
R 20b739a1a421bb63bda38b88ca775180
U drh
Z 96e782ab6ce077a32cb4132dcba512bf
Z 26c391a6fcfb2f70f6b3966c96a404f9

2
manifest.uuid
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@ -1 +1 @@
384909e50f4ae2e84534f9a6505cfb5cc9f4d6ca
f9372072a6d6caa15fa14ec722523944470fe155

788
src/printf.c Normal file
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@ -0,0 +1,788 @@
/*
** The "printf" code that follows dates from the 1980's. It is in
** the public domain. The original comments are included here for
** completeness. They are slightly out-of-date.
**
** The following modules is an enhanced replacement for the "printf" programs
** found in the standard library. The following enhancements are
** supported:
**
** + Additional functions. The standard set of "printf" functions
** includes printf, fprintf, sprintf, vprintf, vfprintf, and
** vsprintf. This module adds the following:
**
** * snprintf -- Works like sprintf, but has an extra argument
** which is the size of the buffer written to.
**
** * mprintf -- Similar to sprintf. Writes output to memory
** obtained from malloc.
**
** * xprintf -- Calls a function to dispose of output.
**
** * nprintf -- No output, but returns the number of characters
** that would have been output by printf.
**
** * A v- version (ex: vsnprintf) of every function is also
** supplied.
**
** + A few extensions to the formatting notation are supported:
**
** * The "=" flag (similar to "-") causes the output to be
** be centered in the appropriately sized field.
**
** * The %b field outputs an integer in binary notation.
**
** * The %c field now accepts a precision. The character output
** is repeated by the number of times the precision specifies.
**
** * The %' field works like %c, but takes as its character the
** next character of the format string, instead of the next
** argument. For example, printf("%.78'-") prints 78 minus
** signs, the same as printf("%.78c",'-').
**
** + When compiled using GCC on a SPARC, this version of printf is
** faster than the library printf for SUN OS 4.1.
**
** + All functions are fully reentrant.
**
*/
#include "sqliteInt.h"
/*
** Undefine COMPATIBILITY to make some slight changes in the way things
** work. I think the changes are an improvement, but they are not
** backwards compatible.
*/
/* #define COMPATIBILITY / * Compatible with SUN OS 4.1 */
/*
** Conversion types fall into various categories as defined by the
** following enumeration.
*/
enum et_type { /* The type of the format field */
etRADIX, /* Integer types. %d, %x, %o, and so forth */
etFLOAT, /* Floating point. %f */
etEXP, /* Exponentional notation. %e and %E */
etGENERIC, /* Floating or exponential, depending on exponent. %g */
etSIZE, /* Return number of characters processed so far. %n */
etSTRING, /* Strings. %s */
etPERCENT, /* Percent symbol. %% */
etCHARX, /* Characters. %c */
etERROR, /* Used to indicate no such conversion type */
/* The rest are extensions, not normally found in printf() */
etCHARLIT, /* Literal characters. %' */
etSQLESCAPE, /* Strings with '\'' doubled. %q */
etORDINAL /* 1st, 2nd, 3rd and so forth */
};
/*
** Each builtin conversion character (ex: the 'd' in "%d") is described
** by an instance of the following structure
*/
typedef struct et_info { /* Information about each format field */
int fmttype; /* The format field code letter */
int base; /* The base for radix conversion */
char *charset; /* The character set for conversion */
int flag_signed; /* Is the quantity signed? */
char *prefix; /* Prefix on non-zero values in alt format */
enum et_type type; /* Conversion paradigm */
} et_info;
/*
** The following table is searched linearly, so it is good to put the
** most frequently used conversion types first.
*/
static et_info fmtinfo[] = {
{ 'd', 10, "0123456789", 1, 0, etRADIX, },
{ 's', 0, 0, 0, 0, etSTRING, },
{ 'q', 0, 0, 0, 0, etSQLESCAPE, },
{ 'c', 0, 0, 0, 0, etCHARX, },
{ 'o', 8, "01234567", 0, "0", etRADIX, },
{ 'u', 10, "0123456789", 0, 0, etRADIX, },
{ 'x', 16, "0123456789abcdef", 0, "x0", etRADIX, },
{ 'X', 16, "0123456789ABCDEF", 0, "X0", etRADIX, },
{ 'r', 10, "0123456789", 0, 0, etORDINAL, },
{ 'f', 0, 0, 1, 0, etFLOAT, },
{ 'e', 0, "e", 1, 0, etEXP, },
{ 'E', 0, "E", 1, 0, etEXP, },
{ 'g', 0, "e", 1, 0, etGENERIC, },
{ 'G', 0, "E", 1, 0, etGENERIC, },
{ 'i', 10, "0123456789", 1, 0, etRADIX, },
{ 'n', 0, 0, 0, 0, etSIZE, },
{ '%', 0, 0, 0, 0, etPERCENT, },
{ 'b', 2, "01", 0, "b0", etRADIX, }, /* Binary */
{ 'p', 10, "0123456789", 0, 0, etRADIX, }, /* Pointers */
{ '\'', 0, 0, 0, 0, etCHARLIT, }, /* Literal char */
};
#define etNINFO (sizeof(fmtinfo)/sizeof(fmtinfo[0]))
/*
** If NOFLOATINGPOINT is defined, then none of the floating point
** conversions will work.
*/
#ifndef etNOFLOATINGPOINT
/*
** "*val" is a double such that 0.1 <= *val < 10.0
** Return the ascii code for the leading digit of *val, then
** multiply "*val" by 10.0 to renormalize.
**
** Example:
** input: *val = 3.14159
** output: *val = 1.4159 function return = '3'
**
** The counter *cnt is incremented each time. After counter exceeds
** 16 (the number of significant digits in a 64-bit float) '0' is
** always returned.
*/
static int et_getdigit(double *val, int *cnt){
int digit;
double d;
if( (*cnt)++ >= 16 ) return '0';
digit = (int)*val;
d = digit;
digit += '0';
*val = (*val - d)*10.0;
return digit;
}
#endif
#define etBUFSIZE 1000 /* Size of the output buffer */
/*
** The root program. All variations call this core.
**
** INPUTS:
** func This is a pointer to a function taking three arguments
** 1. A pointer to anything. Same as the "arg" parameter.
** 2. A pointer to the list of characters to be output
** (Note, this list is NOT null terminated.)
** 3. An integer number of characters to be output.
** (Note: This number might be zero.)
**
** arg This is the pointer to anything which will be passed as the
** first argument to "func". Use it for whatever you like.
**
** fmt This is the format string, as in the usual print.
**
** ap This is a pointer to a list of arguments. Same as in
** vfprint.
**
** OUTPUTS:
** The return value is the total number of characters sent to
** the function "func". Returns -1 on a error.
**
** Note that the order in which automatic variables are declared below
** seems to make a big difference in determining how fast this beast
** will run.
*/
static int vxprintf(
void (*func)(void*,char*,int),
void *arg,
const char *format,
va_list ap
){
register const char *fmt; /* The format string. */
register int c; /* Next character in the format string */
register char *bufpt; /* Pointer to the conversion buffer */
register int precision; /* Precision of the current field */
register int length; /* Length of the field */
register int idx; /* A general purpose loop counter */
int count; /* Total number of characters output */
int width; /* Width of the current field */
int flag_leftjustify; /* True if "-" flag is present */
int flag_plussign; /* True if "+" flag is present */
int flag_blanksign; /* True if " " flag is present */
int flag_alternateform; /* True if "#" flag is present */
int flag_zeropad; /* True if field width constant starts with zero */
int flag_long; /* True if "l" flag is present */
int flag_center; /* True if "=" flag is present */
unsigned long longvalue; /* Value for integer types */
double realvalue; /* Value for real types */
et_info *infop; /* Pointer to the appropriate info structure */
char buf[etBUFSIZE]; /* Conversion buffer */
char prefix; /* Prefix character. "+" or "-" or " " or '\0'. */
int errorflag = 0; /* True if an error is encountered */
enum et_type xtype; /* Conversion paradigm */
char *zMem; /* String to be freed */
char *zExtra; /* Extra memory used for etTCLESCAPE conversions */
static char spaces[] = " "
" ";
#define etSPACESIZE (sizeof(spaces)-1)
#ifndef etNOFLOATINGPOINT
int exp; /* exponent of real numbers */
double rounder; /* Used for rounding floating point values */
int flag_dp; /* True if decimal point should be shown */
int flag_rtz; /* True if trailing zeros should be removed */
int flag_exp; /* True to force display of the exponent */
int nsd; /* Number of significant digits returned */
#endif
fmt = format; /* Put in a register for speed */
count = length = 0;
bufpt = 0;
for(; (c=(*fmt))!=0; ++fmt){
if( c!='%' ){
register int amt;
bufpt = (char *)fmt;
amt = 1;
while( (c=(*++fmt))!='%' && c!=0 ) amt++;
(*func)(arg,bufpt,amt);
count += amt;
if( c==0 ) break;
}
if( (c=(*++fmt))==0 ){
errorflag = 1;
(*func)(arg,"%",1);
count++;
break;
}
/* Find out what flags are present */
flag_leftjustify = flag_plussign = flag_blanksign =
flag_alternateform = flag_zeropad = flag_center = 0;
do{
switch( c ){
case '-': flag_leftjustify = 1; c = 0; break;
case '+': flag_plussign = 1; c = 0; break;
case ' ': flag_blanksign = 1; c = 0; break;
case '#': flag_alternateform = 1; c = 0; break;
case '0': flag_zeropad = 1; c = 0; break;
case '=': flag_center = 1; c = 0; break;
default: break;
}
}while( c==0 && (c=(*++fmt))!=0 );
if( flag_center ) flag_leftjustify = 0;
/* Get the field width */
width = 0;
if( c=='*' ){
width = va_arg(ap,int);
if( width<0 ){
flag_leftjustify = 1;
width = -width;
}
c = *++fmt;
}else{
while( isdigit(c) ){
width = width*10 + c - '0';
c = *++fmt;
}
}
if( width > etBUFSIZE-10 ){
width = etBUFSIZE-10;
}
/* Get the precision */
if( c=='.' ){
precision = 0;
c = *++fmt;
if( c=='*' ){
precision = va_arg(ap,int);
#ifndef etCOMPATIBILITY
/* This is sensible, but SUN OS 4.1 doesn't do it. */
if( precision<0 ) precision = -precision;
#endif
c = *++fmt;
}else{
while( isdigit(c) ){
precision = precision*10 + c - '0';
c = *++fmt;
}
}
/* Limit the precision to prevent overflowing buf[] during conversion */
if( precision>etBUFSIZE-40 ) precision = etBUFSIZE-40;
}else{
precision = -1;
}
/* Get the conversion type modifier */
if( c=='l' ){
flag_long = 1;
c = *++fmt;
}else{
flag_long = 0;
}
/* Fetch the info entry for the field */
infop = 0;
for(idx=0; idx<etNINFO; idx++){
if( c==fmtinfo[idx].fmttype ){
infop = &fmtinfo[idx];
break;
}
}
/* No info entry found. It must be an error. */
if( infop==0 ){
xtype = etERROR;
}else{
xtype = infop->type;
}
zExtra = 0;
/*
** At this point, variables are initialized as follows:
**
** flag_alternateform TRUE if a '#' is present.
** flag_plussign TRUE if a '+' is present.
** flag_leftjustify TRUE if a '-' is present or if the
** field width was negative.
** flag_zeropad TRUE if the width began with 0.
** flag_long TRUE if the letter 'l' (ell) prefixed
** the conversion character.
** flag_blanksign TRUE if a ' ' is present.
** width The specified field width. This is
** always non-negative. Zero is the default.
** precision The specified precision. The default
** is -1.
** xtype The class of the conversion.
** infop Pointer to the appropriate info struct.
*/
switch( xtype ){
case etORDINAL:
case etRADIX:
if( flag_long ) longvalue = va_arg(ap,long);
else longvalue = va_arg(ap,int);
#ifdef etCOMPATIBILITY
/* For the format %#x, the value zero is printed "0" not "0x0".
** I think this is stupid. */
if( longvalue==0 ) flag_alternateform = 0;
#else
/* More sensible: turn off the prefix for octal (to prevent "00"),
** but leave the prefix for hex. */
if( longvalue==0 && infop->base==8 ) flag_alternateform = 0;
#endif
if( infop->flag_signed ){
if( *(long*)&longvalue<0 ){
longvalue = -*(long*)&longvalue;
prefix = '-';
}else if( flag_plussign ) prefix = '+';
else if( flag_blanksign ) prefix = ' ';
else prefix = 0;
}else prefix = 0;
if( flag_zeropad && precision<width-(prefix!=0) ){
precision = width-(prefix!=0);
}
bufpt = &buf[etBUFSIZE];
if( xtype==etORDINAL ){
long a,b;
a = longvalue%10;
b = longvalue%100;
bufpt -= 2;
if( a==0 || a>3 || (b>10 && b<14) ){
bufpt[0] = 't';
bufpt[1] = 'h';
}else if( a==1 ){
bufpt[0] = 's';
bufpt[1] = 't';
}else if( a==2 ){
bufpt[0] = 'n';
bufpt[1] = 'd';
}else if( a==3 ){
bufpt[0] = 'r';
bufpt[1] = 'd';
}
}
{
register char *cset; /* Use registers for speed */
register int base;
cset = infop->charset;
base = infop->base;
do{ /* Convert to ascii */
*(--bufpt) = cset[longvalue%base];
longvalue = longvalue/base;
}while( longvalue>0 );
}
length = (long)&buf[etBUFSIZE]-(long)bufpt;
for(idx=precision-length; idx>0; idx--){
*(--bufpt) = '0'; /* Zero pad */
}
if( prefix ) *(--bufpt) = prefix; /* Add sign */
if( flag_alternateform && infop->prefix ){ /* Add "0" or "0x" */
char *pre, x;
pre = infop->prefix;
if( *bufpt!=pre[0] ){
for(pre=infop->prefix; (x=(*pre))!=0; pre++) *(--bufpt) = x;
}
}
length = (long)&buf[etBUFSIZE]-(long)bufpt;
break;
case etFLOAT:
case etEXP:
case etGENERIC:
realvalue = va_arg(ap,double);
#ifndef etNOFLOATINGPOINT
if( precision<0 ) precision = 6; /* Set default precision */
if( precision>etBUFSIZE-10 ) precision = etBUFSIZE-10;
if( realvalue<0.0 ){
realvalue = -realvalue;
prefix = '-';
}else{
if( flag_plussign ) prefix = '+';
else if( flag_blanksign ) prefix = ' ';
else prefix = 0;
}
if( infop->type==etGENERIC && precision>0 ) precision--;
rounder = 0.0;
#ifdef COMPATIBILITY
/* Rounding works like BSD when the constant 0.4999 is used. Wierd! */
for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
#else
/* It makes more sense to use 0.5 */
for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1);
#endif
if( infop->type==etFLOAT ) realvalue += rounder;
/* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
exp = 0;
if( realvalue>0.0 ){
int k = 0;
while( realvalue>=1e8 && k++<100 ){ realvalue *= 1e-8; exp+=8; }
while( realvalue>=10.0 && k++<100 ){ realvalue *= 0.1; exp++; }
while( realvalue<1e-8 && k++<100 ){ realvalue *= 1e8; exp-=8; }
while( realvalue<1.0 && k++<100 ){ realvalue *= 10.0; exp--; }
if( k>=100 ){
bufpt = "NaN";
length = 3;
break;
}
}
bufpt = buf;
/*
** If the field type is etGENERIC, then convert to either etEXP
** or etFLOAT, as appropriate.
*/
flag_exp = xtype==etEXP;
if( xtype!=etFLOAT ){
realvalue += rounder;
if( realvalue>=10.0 ){ realvalue *= 0.1; exp++; }
}
if( xtype==etGENERIC ){
flag_rtz = !flag_alternateform;
if( exp<-4 || exp>precision ){
xtype = etEXP;
}else{
precision = precision - exp;
xtype = etFLOAT;
}
}else{
flag_rtz = 0;
}
/*
** The "exp+precision" test causes output to be of type etEXP if
** the precision is too large to fit in buf[].
*/
nsd = 0;
if( xtype==etFLOAT && exp+precision<etBUFSIZE-30 ){
flag_dp = (precision>0 || flag_alternateform);
if( prefix ) *(bufpt++) = prefix; /* Sign */
if( exp<0 ) *(bufpt++) = '0'; /* Digits before "." */
else for(; exp>=0; exp--) *(bufpt++) = et_getdigit(&realvalue,&nsd);
if( flag_dp ) *(bufpt++) = '.'; /* The decimal point */
for(exp++; exp<0 && precision>0; precision--, exp++){
*(bufpt++) = '0';
}
while( (precision--)>0 ) *(bufpt++) = et_getdigit(&realvalue,&nsd);
*(bufpt--) = 0; /* Null terminate */
if( flag_rtz && flag_dp ){ /* Remove trailing zeros and "." */
while( bufpt>=buf && *bufpt=='0' ) *(bufpt--) = 0;
if( bufpt>=buf && *bufpt=='.' ) *(bufpt--) = 0;
}
bufpt++; /* point to next free slot */
}else{ /* etEXP or etGENERIC */
flag_dp = (precision>0 || flag_alternateform);
if( prefix ) *(bufpt++) = prefix; /* Sign */
*(bufpt++) = et_getdigit(&realvalue,&nsd); /* First digit */
if( flag_dp ) *(bufpt++) = '.'; /* Decimal point */
while( (precision--)>0 ) *(bufpt++) = et_getdigit(&realvalue,&nsd);
bufpt--; /* point to last digit */
if( flag_rtz && flag_dp ){ /* Remove tail zeros */
while( bufpt>=buf && *bufpt=='0' ) *(bufpt--) = 0;
if( bufpt>=buf && *bufpt=='.' ) *(bufpt--) = 0;
}
bufpt++; /* point to next free slot */
if( exp || flag_exp ){
*(bufpt++) = infop->charset[0];
if( exp<0 ){ *(bufpt++) = '-'; exp = -exp; } /* sign of exp */
else { *(bufpt++) = '+'; }
if( exp>=100 ){
*(bufpt++) = (exp/100)+'0'; /* 100's digit */
exp %= 100;
}
*(bufpt++) = exp/10+'0'; /* 10's digit */
*(bufpt++) = exp%10+'0'; /* 1's digit */
}
}
/* The converted number is in buf[] and zero terminated. Output it.
** Note that the number is in the usual order, not reversed as with
** integer conversions. */
length = (long)bufpt-(long)buf;
bufpt = buf;
/* Special case: Add leading zeros if the flag_zeropad flag is
** set and we are not left justified */
if( flag_zeropad && !flag_leftjustify && length < width){
int i;
int nPad = width - length;
for(i=width; i>=nPad; i--){
bufpt[i] = bufpt[i-nPad];
}
i = prefix!=0;
while( nPad-- ) bufpt[i++] = '0';
length = width;
}
#endif
break;
case etSIZE:
*(va_arg(ap,int*)) = count;
length = width = 0;
break;
case etPERCENT:
buf[0] = '%';
bufpt = buf;
length = 1;
break;
case etCHARLIT:
case etCHARX:
c = buf[0] = (xtype==etCHARX ? va_arg(ap,int) : *++fmt);
if( precision>=0 ){
for(idx=1; idx<precision; idx++) buf[idx] = c;
length = precision;
}else{
length =1;
}
bufpt = buf;
break;
case etSTRING:
zMem = bufpt = va_arg(ap,char*);
if( bufpt==0 ) bufpt = "(null)";
length = strlen(bufpt);
if( precision>=0 && precision<length ) length = precision;
break;
case etSQLESCAPE:
{
int i, j, n, c;
char *arg = va_arg(ap,char*);
if( arg==0 ) arg = "(NULL)";
for(i=n=0; (c=arg[i])!=0; i++){
if( c=='\'' ) n++;
}
n += i;
if( n>etBUFSIZE ){
bufpt = zExtra = sqliteMalloc( n );
}else{
bufpt = buf;
}
for(i=j=0; (c=arg[i])!=0; i++){
bufpt[j++] = c;
if( c=='\'' ) bufpt[j++] = c;
}
bufpt[j] = 0;
length = j;
if( precision>=0 && precision<length ) length = precision;
}
break;
case etERROR:
buf[0] = '%';
buf[1] = c;
errorflag = 0;
idx = 1+(c!=0);
(*func)(arg,"%",idx);
count += idx;
if( c==0 ) fmt--;
break;
}/* End switch over the format type */
/*
** The text of the conversion is pointed to by "bufpt" and is
** "length" characters long. The field width is "width". Do
** the output.
*/
if( !flag_leftjustify ){
register int nspace;
nspace = width-length;
if( nspace>0 ){
if( flag_center ){
nspace = nspace/2;
width -= nspace;
flag_leftjustify = 1;
}
count += nspace;
while( nspace>=etSPACESIZE ){
(*func)(arg,spaces,etSPACESIZE);
nspace -= etSPACESIZE;
}
if( nspace>0 ) (*func)(arg,spaces,nspace);
}
}
if( length>0 ){
(*func)(arg,bufpt,length);
count += length;
}
if( flag_leftjustify ){
register int nspace;
nspace = width-length;
if( nspace>0 ){
count += nspace;
while( nspace>=etSPACESIZE ){
(*func)(arg,spaces,etSPACESIZE);
nspace -= etSPACESIZE;
}
if( nspace>0 ) (*func)(arg,spaces,nspace);
}
}
if( zExtra ){
sqliteFree(zExtra);
}
}/* End for loop over the format string */
return errorflag ? -1 : count;
} /* End of function */
/* This structure is used to store state information about the
** write to memory that is currently in progress.
*/
struct sgMprintf {
char *zBase; /* A base allocation */
char *zText; /* The string collected so far */
int nChar; /* Length of the string so far */
int nAlloc; /* Amount of space allocated in zText */
};
/*
** This function implements the callback from vxprintf.
**
** This routine add nNewChar characters of text in zNewText to
** the sgMprintf structure pointed to by "arg".
*/
static void mout(void *arg, char *zNewText, int nNewChar){
struct sgMprintf *pM = (struct sgMprintf*)arg;
if( pM->nChar + nNewChar + 1 > pM->nAlloc ){
pM->nAlloc = pM->nChar + nNewChar*2 + 1;
if( pM->zText==pM->zBase ){
pM->zText = sqliteMalloc(pM->nAlloc);
if( pM->zText && pM->nChar ) memcpy(pM->zText,pM->zBase,pM->nChar);
}else{
pM->zText = sqliteRealloc(pM->zText, pM->nAlloc);
}
}
if( pM->zText ){
memcpy(&pM->zText[pM->nChar], zNewText, nNewChar);
pM->nChar += nNewChar;
pM->zText[pM->nChar] = 0;
}
}
/*
** sqlite_mprintf() works like printf(), but allocations memory to hold the
** resulting string and returns a pointer to the allocated memory. Use
** sqliteFree() to release the memory allocated.
*/
char *sqlite_mprintf(const char *zFormat, ...){
va_list ap;
struct sgMprintf sMprintf;
char *zNew;
char zBuf[200];
sMprintf.nChar = 0;
sMprintf.nAlloc = sizeof(zBuf);
sMprintf.zText = zBuf;
sMprintf.zBase = zBuf;
va_start(ap,zFormat);
vxprintf(mout,&sMprintf,zFormat,ap);
va_end(ap);
sMprintf.zText[sMprintf.nChar] = 0;
if( sMprintf.zText==sMprintf.zBase ){
zNew = sqliteMalloc( sMprintf.nChar+1 );
if( zNew ) strcpy(zNew,zBuf);
}else{
zNew = sqliteRealloc(sMprintf.zText,sMprintf.nChar+1);
}
return zNew;
}
/* This is the varargs version of sqlite_mprintf.
*/
char *sqlite_vmprintf(const char *zFormat, va_list ap){
struct sgMprintf sMprintf;
char zBuf[200];
sMprintf.nChar = 0;
sMprintf.zText = zBuf;
sMprintf.nAlloc = sizeof(zBuf);
sMprintf.zBase = zBuf;
vxprintf(mout,&sMprintf,zFormat,ap);
sMprintf.zText[sMprintf.nChar] = 0;
if( sMprintf.zText==sMprintf.zBase ){
sMprintf.zText = sqliteMalloc( strlen(zBuf)+1 );
if( sMprintf.zText ) strcpy(sMprintf.zText,zBuf);
}else{
sMprintf.zText = sqliteRealloc(sMprintf.zText,sMprintf.nChar+1);
}
return sMprintf.zText;
}
/*
** The following four routines implement the varargs versions of the
** sqlite_exec() and sqlite_get_table() interfaces. See the sqlite.h
** header files for a more detailed description of how these interfaces
** work.
**
** These routines are all just simple wrappers.
*/
int sqlite_exec_printf(
sqlite *db, /* An open database */
char *sqlFormat, /* printf-style format string for the SQL */
sqlite_callback xCallback, /* Callback function */
void *pArg, /* 1st argument to callback function */
char **errmsg, /* Error msg written here */
... /* Arguments to the format string. */
){
va_list ap;
int rc;
va_start(ap, errmsg);
rc = sqlite_exec_vprintf(db, sqlFormat, xCallback, pArg, errmsg, ap);
va_end(ap);
return rc;
}
int sqlite_exec_vprintf(
sqlite *db, /* An open database */
char *sqlFormat, /* printf-style format string for the SQL */
sqlite_callback xCallback, /* Callback function */
void *pArg, /* 1st argument to callback function */
char **errmsg, /* Error msg written here */
va_list ap /* Arguments to the format string. */
){
char *zSql;
int rc;
zSql = sqlite_vmprintf(sqlFormat, ap);
rc = sqlite_exec(db, zSql, xCallback, pArg, errmsg);
sqliteFree(zSql);
return rc;
}
int sqlite_get_table_printf(
sqlite *db, /* An open database */
char *sqlFormat, /* printf-style format string for the SQL */
char ***resultp, /* Result written to a char *[] that this points to */
int *nrow, /* Number of result rows written here */
int *ncol, /* Number of result columns written here */
char **errmsg, /* Error msg written here */
... /* Arguments to the format string */
){
va_list ap;
int rc;
va_start(ap, errmsg);
rc = sqlite_get_table_vprintf(db, sqlFormat, resultp, nrow, ncol, errmsg, ap);
va_end(ap);
return rc;
}
int sqlite_get_table_vprintf(
sqlite *db, /* An open database */
char *sqlFormat, /* printf-style format string for the SQL */
char ***resultp, /* Result written to a char *[] that this points to */
int *nrow, /* Number of result rows written here */
int *ncolumn, /* Number of result columns written here */
char **errmsg, /* Error msg written here */
va_list ap /* Arguments to the format string */
){
char *zSql;
int rc;
zSql = sqlite_vmprintf(sqlFormat, ap);
rc = sqlite_get_table(db, zSql, resultp, nrow, ncolumn, errmsg);
sqliteFree(zSql);
return rc;
}

89
src/shell.c
View File

@ -24,7 +24,7 @@
** This file contains code to implement the "sqlite" command line
** utility for accessing SQLite databases.
**
** $Id: shell.c,v 1.25 2000/09/29 13:30:55 drh Exp $
** $Id: shell.c,v 1.26 2000/10/08 22:20:58 drh Exp $
*/
#include <stdlib.h>
#include <string.h>
@ -377,14 +377,15 @@ static int dump_callback(void *pArg, int nArg, char **azArg, char **azCol){
fprintf(pData->out, "%s;\n", azArg[2]);
if( strcmp(azArg[1],"table")==0 ){
struct callback_data d2;
char zSql[1000];
d2 = *pData;
d2.mode = MODE_List;
d2.escape = '\t';
strcpy(d2.separator,"\t");
fprintf(pData->out, "COPY '%s' FROM STDIN;\n", azArg[0]);
sprintf(zSql, "SELECT * FROM '%s'", azArg[0]);
sqlite_exec(pData->db, zSql, callback, &d2, 0);
sqlite_exec_printf(pData->db,
"SELECT * FROM '%q'",
callback, &d2, 0, azArg[0]
);
fprintf(pData->out, "\\.\n");
}
fprintf(pData->out, "VACUUM '%s';\n", azArg[0]);
@ -449,19 +450,22 @@ static void do_meta_command(char *zLine, sqlite *db, struct callback_data *p){
if( c=='d' && strncmp(azArg[0], "dump", n)==0 ){
char *zErrMsg = 0;
char zSql[1000];
if( nArg==1 ){
sprintf(zSql, "SELECT name, type, sql FROM sqlite_master "
"WHERE type!='meta' "
"ORDER BY tbl_name, type DESC, name");
sqlite_exec(db, zSql, dump_callback, p, &zErrMsg);
sqlite_exec(db,
"SELECT name, type, sql FROM sqlite_master "
"WHERE type!='meta' "
"ORDER BY tbl_name, type DESC, name",
dump_callback, p, &zErrMsg
);
}else{
int i;
for(i=1; i<nArg && zErrMsg==0; i++){
sprintf(zSql, "SELECT name, type, sql FROM sqlite_master "
"WHERE tbl_name LIKE '%.800s' AND type!='meta' "
"ORDER BY type DESC, name", azArg[i]);
sqlite_exec(db, zSql, dump_callback, p, &zErrMsg);
sqlite_exec_printf(db,
"SELECT name, type, sql FROM sqlite_master "
"WHERE tbl_name LIKE '%q' AND type!='meta' "
"ORDER BY type DESC, name",
dump_callback, p, &zErrMsg, azArg[i]
);
}
}
@ -507,14 +511,15 @@ static void do_meta_command(char *zLine, sqlite *db, struct callback_data *p){
if( c=='i' && strncmp(azArg[0], "indices", n)==0 && nArg>1 ){
struct callback_data data;
char *zErrMsg = 0;
char zSql[1000];
memcpy(&data, p, sizeof(data));
data.showHeader = 0;
data.mode = MODE_List;
sprintf(zSql, "SELECT name FROM sqlite_master "
"WHERE type='index' AND tbl_name LIKE '%.800s' "
"ORDER BY name", azArg[1]);
sqlite_exec(db, zSql, callback, &data, &zErrMsg);
sqlite_exec_printf(db,
"SELECT name FROM sqlite_master "
"WHERE type='index' AND tbl_name LIKE '%q' "
"ORDER BY name",
callback, &data, &zErrMsg, azArg[1]
);
if( zErrMsg ){
fprintf(stderr,"Error: %s\n", zErrMsg);
free(zErrMsg);
@ -559,21 +564,37 @@ static void do_meta_command(char *zLine, sqlite *db, struct callback_data *p){
if( c=='s' && strncmp(azArg[0], "schema", n)==0 ){
struct callback_data data;
char *zErrMsg = 0;
char zSql[1000];
memcpy(&data, p, sizeof(data));
data.showHeader = 0;
data.mode = MODE_Semi;
if( nArg>1 ){
sprintf(zSql, "SELECT sql FROM sqlite_master "
"WHERE tbl_name LIKE '%.800s' AND type!='meta'"
"ORDER BY type DESC, name",
azArg[1]);
if( sqliteStrICmp(azArg[1],"sqlite_master")==0 ){
char *new_argv[2], *new_colv[2];
new_argv[0] = "CREATE TABLE sqlite_master (\n"
" type text,\n"
" name text,\n"
" tbl_name text,\n"
" sql text\n"
")";
new_argv[1] = 0;
new_colv[0] = "sql";
new_colv[1] = 0;
callback(&data, 1, new_argv, new_colv);
}else{
sqlite_exec_printf(db,
"SELECT sql FROM sqlite_master "
"WHERE tbl_name LIKE '%q' AND type!='meta'"
"ORDER BY type DESC, name",
callback, &data, &zErrMsg, azArg[1]);
}
}else{
sprintf(zSql, "SELECT sql FROM sqlite_master "
sqlite_exec(db,
"SELECT sql FROM sqlite_master "
"WHERE type!='meta' "
"ORDER BY tbl_name, type DESC, name");
"ORDER BY tbl_name, type DESC, name",
callback, &data, &zErrMsg
);
}
sqlite_exec(db, zSql, callback, &data, &zErrMsg);
if( zErrMsg ){
fprintf(stderr,"Error: %s\n", zErrMsg);
free(zErrMsg);
@ -588,19 +609,21 @@ static void do_meta_command(char *zLine, sqlite *db, struct callback_data *p){
char **azResult;
int nRow, rc;
char *zErrMsg;
char zSql[1000];
if( nArg==1 ){
sprintf(zSql,
rc = sqlite_get_table(db,
"SELECT name FROM sqlite_master "
"WHERE type='table' "
"ORDER BY name");
"ORDER BY name",
&azResult, &nRow, 0, &zErrMsg
);
}else{
sprintf(zSql,
rc = sqlite_get_table_printf(db,
"SELECT name FROM sqlite_master "
"WHERE type='table' AND name LIKE '%%%.100s%%' "
"ORDER BY name", azArg[1]);
"WHERE type='table' AND name LIKE '%%%q%%' "
"ORDER BY name",
&azResult, &nRow, 0, &zErrMsg, azArg[1]
);
}
rc = sqlite_get_table(db, zSql, &azResult, &nRow, 0, &zErrMsg);
if( zErrMsg ){
fprintf(stderr,"Error: %s\n", zErrMsg);
free(zErrMsg);

115
src/sqlite.h.in
View File

@ -24,10 +24,11 @@
** This header file defines the interface that the sqlite library
** presents to client programs.
**
** @(#) $Id: sqlite.h.in,v 1.3 2000/09/29 13:30:55 drh Exp $
** @(#) $Id: sqlite.h.in,v 1.4 2000/10/08 22:20:58 drh Exp $
*/
#ifndef _SQLITE_H_
#define _SQLITE_H_
#include <stdarg.h> /* Needed for the definition of va_list */
/*
** The version of the SQLite library.
@ -187,12 +188,39 @@ void sqlite_busy_timeout(sqlite*, int ms);
** Instead of invoking a user-supplied callback for each row of the
** result, this routine remembers each row of the result in memory
** obtained from malloc(), then returns all of the result after the
** query has finished. After the calling function has finished using
** the result, it should pass the result data pointer to
** sqlite_free_table() in order to release the memory that was malloc-ed.
** Because of the way the malloc() happens, the calling function must
** not try to call malloc() directly. Only sqlite_free_table() is able
** to release the memory properly and safely.
** query has finished.
**
** As an example, suppose the query result where this table:
**
** Name | Age
** -----------------------
** Alice | 43
** Bob | 28
** Cindy | 21
**
** If the 3rd argument were &azResult then after the function returns
** azResult would contain the following data:
**
** azResult[0] = "Name";
** azResult[1] = "Age";
** azResult[2] = "Alice";
** azResult[3] = "43";
** azResult[4] = "Bob";
** azResult[5] = "28";
** azResult[6] = "Cindy";
** azResult[7] = "21";
**
** Notice that there is an extra row of data containing the column
** headers. But the *nrow return value is still 3. *ncolumn is
** set to 2. In general, the number of values inserted into azResult
** will be ((*nrow) + 1)*(*ncolumn).
**
** After the calling function has finished using the result, it should
** pass the result data pointer to sqlite_free_table() in order to
** release the memory that was malloc-ed. Because of the way the
** malloc() happens, the calling function must not try to call
** malloc() directly. Only sqlite_free_table() is able to release
** the memory properly and safely.
**
** The return value of this routine is the same as from sqlite_exec().
*/
@ -210,5 +238,78 @@ int sqlite_get_table(
*/
void sqlite_free_table(char **result);
/*
** The following routines are wrappers around sqlite_exec() and
** sqlite_get_table(). The only difference between the routine that
** follow and the originals is that the second argument to the
** routines that follow is really a printf()-style format
** string describing the SQL to be executed. Arguments to the format
** string appear at the end of the argument list.
**
** All of the usual printf formatting options apply. In addition, there
** is a "%q" option. %q works like %s in that it substitutes a null-terminated
** string from the argument list. But %q also double every '\'' character.
** %q is designed for use inside a string literal. By doubling each '\''
** character is escapes that character and allows it to be inserted into
** the string.
**
** For example, so some string variable contains text as follows:
**
** char *zText = "It's a happy day!";
**
** We can use this text in an SQL statement as follows:
**
** sqlite_exec_printf(db, "INSERT INTO table VALUES('%q')",
** callback1, 0, 0, zText);
**
** Because the %q format string is used, the '\'' character in zText
** is escaped and the SQL generated is as follows:
**
** INSERT INTO table1 VALUES('It''s a happy day!')
**
** This is correct. Had we used %s instead of %q, the generated SQL
** would have looked like this:
**
** INSERT INTO table1 VALUES('It's a happy day!');
**
** This second example is an SQL syntax error. As a general rule you
** should always use %q instead of %s when inserting text into a string
** literal.
*/
int sqlite_exec_printf(
sqlite*, /* An open database */
char *sqlFormat, /* printf-style format string for the SQL */
sqlite_callback, /* Callback function */
void *, /* 1st argument to callback function */
char **errmsg, /* Error msg written here */
... /* Arguments to the format string. */
);
int sqlite_exec_vprintf(
sqlite*, /* An open database */
char *sqlFormat, /* printf-style format string for the SQL */
sqlite_callback, /* Callback function */
void *, /* 1st argument to callback function */
char **errmsg, /* Error msg written here */
va_list ap /* Arguments to the format string. */
);
int sqlite_get_table_printf(
sqlite*, /* An open database */
char *sqlFormat, /* printf-style format string for the SQL */
char ***resultp, /* Result written to a char *[] that this points to */
int *nrow, /* Number of result rows written here */
int *ncolumn, /* Number of result columns written here */
char **errmsg, /* Error msg written here */
... /* Arguments to the format string */
);
int sqlite_get_table_vprintf(
sqlite*, /* An open database */
char *sqlFormat, /* printf-style format string for the SQL */
char ***resultp, /* Result written to a char *[] that this points to */
int *nrow, /* Number of result rows written here */
int *ncolumn, /* Number of result columns written here */
char **errmsg, /* Error msg written here */
va_list ap /* Arguments to the format string */
);
#endif /* _SQLITE_H_ */

152
www/c_interface.tcl
View File

@ -1,7 +1,7 @@
#
# Run this Tcl script to generate the sqlite.html file.
#
set rcsid {$Id: c_interface.tcl,v 1.8 2000/09/29 13:30:55 drh Exp $}
set rcsid {$Id: c_interface.tcl,v 1.9 2000/10/08 22:20:58 drh Exp $}
puts {<html>
<head>
@ -22,10 +22,9 @@ programming interface.</p>
<h2>The API</h2>
<p>The interface to the SQLite library consists of eight functions
(only the first three of which are required),
one opaque data structure, and some constants used as return
values from sqlite_exec():</p>
<p>The interface to the SQLite library consists of three core functions,
one opaque data structure, and some constants used as return values.
The core interface is as follows:</p>
<blockquote><pre>
typedef struct sqlite sqlite;
@ -42,6 +41,22 @@ int sqlite_exec(
char **errmsg
);
#define SQLITE_OK 0 /* Successful result */
#define SQLITE_INTERNAL 1 /* An internal logic error in SQLite */
#define SQLITE_ERROR 2 /* SQL error or missing database */
#define SQLITE_PERM 3 /* Access permission denied */
#define SQLITE_ABORT 4 /* Callback routine requested an abort */
#define SQLITE_BUSY 5 /* One or more database files are locked */
#define SQLITE_NOMEM 6 /* A malloc() failed */
#define SQLITE_READONLY 7 /* Attempt to write a readonly database */
</pre></blockquote>
<p>Only the three core routines shown above are required to use
SQLite. But there are many other functions that provide
useful interfaces. These extended routines are as follows:
</p>
<blockquote><pre>
int sqlite_get_table(
sqlite*,
char *sql,
@ -61,14 +76,44 @@ void sqlite_busy_timeout(sqlite*, int ms);
const char sqlite_version[];
#define SQLITE_OK 0 /* Successful result */
#define SQLITE_INTERNAL 1 /* An internal logic error in SQLite */
#define SQLITE_ERROR 2 /* SQL error or missing database */
#define SQLITE_PERM 3 /* Access permission denied */
#define SQLITE_ABORT 4 /* Callback routine requested an abort */
#define SQLITE_BUSY 5 /* One or more database files are locked */
#define SQLITE_NOMEM 6 /* A malloc() failed */
#define SQLITE_READONLY 7 /* Attempt to write a readonly database */
int sqlite_exec_printf(
sqlite*,
char *sql,
int (*)(void*,int,char**,char**),
void*,
char **errmsg,
...
);
int sqlite_exec_vprintf(
sqlite*,
char *sql,
int (*)(void*,int,char**,char**),
void*,
char **errmsg,
va_list
);
int sqlite_get_table_printf(
sqlite*,
char *sql,
char ***result,
int *nrow,
int *ncolumn,
char **errmsg,
...
);
int sqlite_get_table_vprintf(
sqlite*,
char *sql,
char ***result,
int *nrow,
int *ncolumn,
char **errmsg,
va_list
);
</pre></blockquote>
<p>All of the above definitions are included in the "sqlite.h"
@ -304,7 +349,7 @@ the SQLITE_VERSION macro against the <b>sqlite_version</b>
string constant to verify that the version number of the
header file and the library match.</p>
<h2>Changing the libraries reponse to locked files</h2>
<h2>Changing the libraries response to locked files</h2>
<p>The GDBM library supports database locks at the file level.
If a GDBM database file is opened for reading, then that same
@ -345,6 +390,85 @@ will wait for the lock to clear for at least the number of milliseconds
specified before it returns SQLITE_BUSY. Specifying zero milliseconds for
the timeout restores the default behavior.</p>
<h2>Using the <tt>_printf()</tt> wrapper functions</h2>
<p>The four utility functions</p>
<p>
<ul>
<li><b>sqlite_exec_printf()</b></li>
<li><b>sqlite_exec_vprintf()</b></li>
<li><b>sqlite_get_table_printf()</b></li>
<li><b>sqlite_get_table_vprintf()</b></li>
</ul>
</p>
<p>implement the same query functionality as <b>sqlite_exec()</b>
and <b>sqlite_get_table()</b>. But instead of taking a complete
SQL statement as their second argument, the four <b>_printf</b>
routines take a printf-style format string. The SQL statement to
be executed is generated from this format string and from whatever
additional arguments are attached to the end of the function call.</p>
<p>There are two advantages to using the SQLite printf
functions instead of <b>sprintf()</b>. First of all, with the
SQLite printf routines, there is never a danger of overflowing a
static buffer as there is with <b>sprintf()</b>. The SQLite
printf routines automatically allocate (and later free)
as much memory as is
necessary to hold the SQL statements generated.</p>
<p>The second advantage the SQLite printf routines have over
<b>sprintf()</b> is a new formatting option specifically designed
to support string literals in SQL. Within the format string,
the %q formatting option works very much like %s in that it
reads a null-terminated string from the argument list and inserts
it into the result. But %q translates the inserted string by
making two copies of every single-quote (') character in the
substituted string. This has the effect of escaping the end-of-string
meaning of single-quote within a string literal.
</p>
<p>Consider an example. Suppose you are trying to insert a string
values into a database table where the string value was obtained from
user input. Suppose the string to be inserted is stored in a variable
named zString. The code to insert this string might look like this:</p>
<blockquote><pre>
sqlite_exec_printf(db,
"INSERT INTO table1 VALUES('%s')",
0, 0, 0, zString);
</pre></blockquote>
<p>If the zString variable holds text like "Hello", then this statement
will work just fine. But suppose the user enters a string like
"Hi y'all!". The SQL statement generated reads as follows:
<blockquote><pre>
INSERT INTO table1 VALUES('Hi y'all')
</pre></blockquote>
<p>This is not valid SQL because of the apostrophy in the word "y'all".
But if the %q formatting option is used instead of %s, like this:</p>
<blockquote><pre>
sqlite_exec_printf(db,
"INSERT INTO table1 VALUES('%q')",
0, 0, 0, zString);
</pre></blockquote>
<p>Then the generated SQL will look like the following:</p>
<blockquote><pre>
INSERT INTO table1 VALUES('Hi y''all')
</pre></blockquote>
<p>Here the apostrophy has been escaped and the SQL statement is well-formed.
When generating SQL on-the-fly from data that might contain a
single-quote character ('), it is always a good idea to use the
SQLite printf routines and the %q formatting option instead of <b>sprintf</b>.
</p>
<h2>Usage Examples</h2>
<p>For examples of how the SQLite C/C++ interface can be used,

8
www/changes.tcl
View File

@ -17,6 +17,14 @@ proc chng {date desc} {
puts "<DD><P><UL>$desc</UL></P></DD>"
}
chng {2000 Oct 8 (1.0.9)} {
<li>Added the <b>sqlite_..._printf()</b> interface routines.</li>
<li>Modified the <b>sqlite</b> shell program to use the new interface
routines.</li>
<li>Modified the <b>sqlite</b> shell program to print the schema for
the built-in SQLITE_MASTER table, if explicitly requested.</li>
}
chng {2000 Sep 30 (1.0.8)} {
<li>Begin writing documentation on the TCL interface.</li>
}

54
www/tclsqlite.tcl
View File

@ -1,7 +1,7 @@
#
# Run this Tcl script to generate the tclsqlite.html file.
#
set rcsid {$Id: tclsqlite.tcl,v 1.1 2000/09/30 22:46:07 drh Exp $}
set rcsid {$Id: tclsqlite.tcl,v 1.2 2000/10/08 22:20:58 drh Exp $}
puts {<html>
<head>
@ -108,7 +108,7 @@ db1 eval {CREATE TABLE t1(a int, b text)}</b>
</blockquote>
<p>The above code creates a new table named <b>t1</b> with columns
<b>a</b> and <b>b</b>. What could be simplier?</p>
<b>a</b> and <b>b</b>. What could be simpler?</p>
<p>Query results are returned as a list of column values. If a
query requests 2 columns and there are 3 rows matching the query,
@ -186,14 +186,58 @@ a=3 b=howdy!</b>
</blockquote>
<h2>The "complete" method</h2>
<i>TBD</i>
<p>
The "complete" method takes a string of supposed SQL as its only argument.
It returns TRUE if the string is a complete statement of SQL and FALSE if
there is more to be entered.</p>
<p>The "complete" method is useful when building interactive applications
in order to know when the user has finished entering a line of SQL code.
This is really just an interface to the <b>sqlite_complete()</b> C
function. Refer to the <a href="c_interface.html">C/C++ interface</a>
specification for additional information.</p>
<h2>The "timeout" method</h2>
<i>TBD</i>
<p>The "timeout" method is used to control how long the SQLite library
will wait for locks to clear before giving up on a database transaction.
The default timeout is 0 millisecond. (In other words, the default behavior
is not to wait at all.)</p>
<p>The GDBM library the underlies SQLite allows multiple simultaneous
readers or a single writer but not both. If any process is writing to
the database no other process is allows to read or write. If any process
is reading the database other processes are allowed to read but not write.
Each GDBM file is locked separately. Because each SQL table is stored as
a separate file, it is possible for different processes to write to different
database tables at the same time, just not the same table.</p>
<p>When SQLite tries to open a GDBM file and finds that it is locked, it
can optionally delay for a short while and try to open the file again.
This process repeats until the query times out and SQLite returns a
failure. The timeout is adjustable. It is set to 0 by default so that
if a GDBM file is locked, the SQL statement fails immediately. But you
can use the "timeout" method to change the timeout value to a positive
number. For example:</p>
<blockquote><b>db1 timeout 2000</b></blockquote>
<p>The argument to the timeout method is the maximum number of milliseconds
to wait for the lock to clear. So in the example above, the maximum delay
would be 2 seconds.</p>
<h2>The "busy" method</h2>
<i>TBD</i>
<p>The "busy" method, like "timeout", only comes into play when a GDBM
file is locked. But the "busy" method gives the programmer much more
control over what action to take. The "busy" method specifies a callback
Tcl procedure that is invoked whenever SQLite tries to open a locked
GDBM file. This callback can do whatever is desired. Presumably, the
callback will do some other useful work for a short while then return
so that the lock can be tried again. The callback procedure should
return "0" if it wants SQLite to try again to open the GDBM file and
should return "1" if it wants SQLite to abandon the current operation.
}