git/quote.c
Pavel Roskin 50e7b06730 [PATCH] quote.c: Make loop control more readable.
quote_c_style_counted() in quote.c uses a hard-to-read  construct.
Convert this to a more traditional form of the for loop.

Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-21 13:28:24 -08:00

269 lines
5.6 KiB
C

#include "cache.h"
#include "quote.h"
/* Help to copy the thing properly quoted for the shell safety.
* any single quote is replaced with '\'', any exclamation point
* is replaced with '\!', and the whole thing is enclosed in a
*
* E.g.
* original sq_quote result
* name ==> name ==> 'name'
* a b ==> a b ==> 'a b'
* a'b ==> a'\''b ==> 'a'\''b'
* a!b ==> a'\!'b ==> 'a'\!'b'
*/
#undef EMIT
#define EMIT(x) ( (++len < n) && (*bp++ = (x)) )
static inline int need_bs_quote(char c)
{
return (c == '\'' || c == '!');
}
size_t sq_quote_buf(char *dst, size_t n, const char *src)
{
char c;
char *bp = dst;
size_t len = 0;
EMIT('\'');
while ((c = *src++)) {
if (need_bs_quote(c)) {
EMIT('\'');
EMIT('\\');
EMIT(c);
EMIT('\'');
} else {
EMIT(c);
}
}
EMIT('\'');
if ( n )
*bp = 0;
return len;
}
char *sq_quote(const char *src)
{
char *buf;
size_t cnt;
cnt = sq_quote_buf(NULL, 0, src) + 1;
buf = xmalloc(cnt);
sq_quote_buf(buf, cnt, src);
return buf;
}
char *sq_dequote(char *arg)
{
char *dst = arg;
char *src = arg;
char c;
if (*src != '\'')
return NULL;
for (;;) {
c = *++src;
if (!c)
return NULL;
if (c != '\'') {
*dst++ = c;
continue;
}
/* We stepped out of sq */
switch (*++src) {
case '\0':
*dst = 0;
return arg;
case '\\':
c = *++src;
if (need_bs_quote(c) && *++src == '\'') {
*dst++ = c;
continue;
}
/* Fallthrough */
default:
return NULL;
}
}
}
/*
* C-style name quoting.
*
* Does one of three things:
*
* (1) if outbuf and outfp are both NULL, inspect the input name and
* counts the number of bytes that are needed to hold c_style
* quoted version of name, counting the double quotes around
* it but not terminating NUL, and returns it. However, if name
* does not need c_style quoting, it returns 0.
*
* (2) if outbuf is not NULL, it must point at a buffer large enough
* to hold the c_style quoted version of name, enclosing double
* quotes, and terminating NUL. Fills outbuf with c_style quoted
* version of name enclosed in double-quote pair. Return value
* is undefined.
*
* (3) if outfp is not NULL, outputs c_style quoted version of name,
* but not enclosed in double-quote pair. Return value is undefined.
*/
static int quote_c_style_counted(const char *name, int namelen,
char *outbuf, FILE *outfp, int no_dq)
{
#undef EMIT
#define EMIT(c) \
(outbuf ? (*outbuf++ = (c)) : outfp ? fputc(c, outfp) : (count++))
#define EMITQ() EMIT('\\')
const char *sp;
int ch, count = 0, needquote = 0;
if (!no_dq)
EMIT('"');
for (sp = name; sp < name + namelen; sp++) {
ch = *sp;
if (!ch)
break;
if ((ch < ' ') || (ch == '"') || (ch == '\\') ||
(ch == 0177)) {
needquote = 1;
switch (ch) {
case '\a': EMITQ(); ch = 'a'; break;
case '\b': EMITQ(); ch = 'b'; break;
case '\f': EMITQ(); ch = 'f'; break;
case '\n': EMITQ(); ch = 'n'; break;
case '\r': EMITQ(); ch = 'r'; break;
case '\t': EMITQ(); ch = 't'; break;
case '\v': EMITQ(); ch = 'v'; break;
case '\\': /* fallthru */
case '"': EMITQ(); break;
case ' ':
break;
default:
/* octal */
EMITQ();
EMIT(((ch >> 6) & 03) + '0');
EMIT(((ch >> 3) & 07) + '0');
ch = (ch & 07) + '0';
break;
}
}
EMIT(ch);
}
if (!no_dq)
EMIT('"');
if (outbuf)
*outbuf = 0;
return needquote ? count : 0;
}
int quote_c_style(const char *name, char *outbuf, FILE *outfp, int no_dq)
{
int cnt = strlen(name);
return quote_c_style_counted(name, cnt, outbuf, outfp, no_dq);
}
/*
* C-style name unquoting.
*
* Quoted should point at the opening double quote. Returns
* an allocated memory that holds unquoted name, which the caller
* should free when done. Updates endp pointer to point at
* one past the ending double quote if given.
*/
char *unquote_c_style(const char *quoted, const char **endp)
{
const char *sp;
char *name = NULL, *outp = NULL;
int count = 0, ch, ac;
#undef EMIT
#define EMIT(c) (outp ? (*outp++ = (c)) : (count++))
if (*quoted++ != '"')
return NULL;
while (1) {
/* first pass counts and allocates, second pass fills */
for (sp = quoted; (ch = *sp++) != '"'; ) {
if (ch == '\\') {
switch (ch = *sp++) {
case 'a': ch = '\a'; break;
case 'b': ch = '\b'; break;
case 'f': ch = '\f'; break;
case 'n': ch = '\n'; break;
case 'r': ch = '\r'; break;
case 't': ch = '\t'; break;
case 'v': ch = '\v'; break;
case '\\': case '"':
break; /* verbatim */
case '0'...'7':
/* octal */
ac = ((ch - '0') << 6);
if ((ch = *sp++) < '0' || '7' < ch)
return NULL;
ac |= ((ch - '0') << 3);
if ((ch = *sp++) < '0' || '7' < ch)
return NULL;
ac |= (ch - '0');
ch = ac;
break;
default:
return NULL; /* malformed */
}
}
EMIT(ch);
}
if (name) {
*outp = 0;
if (endp)
*endp = sp;
return name;
}
outp = name = xmalloc(count + 1);
}
}
void write_name_quoted(const char *prefix, int prefix_len,
const char *name, int quote, FILE *out)
{
int needquote;
if (!quote) {
no_quote:
if (prefix_len)
fprintf(out, "%.*s", prefix_len, prefix);
fputs(name, out);
return;
}
needquote = 0;
if (prefix_len)
needquote = quote_c_style_counted(prefix, prefix_len,
NULL, NULL, 0);
if (!needquote)
needquote = quote_c_style(name, NULL, NULL, 0);
if (needquote) {
fputc('"', out);
if (prefix_len)
quote_c_style_counted(prefix, prefix_len,
NULL, out, 1);
quote_c_style(name, NULL, out, 1);
fputc('"', out);
}
else
goto no_quote;
}