diff options
Diffstat (limited to 'quote.c')
| -rw-r--r-- | quote.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/quote.c b/quote.c new file mode 100644 index 0000000000..06792d47c3 --- /dev/null +++ b/quote.c @@ -0,0 +1,266 @@ +#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; + 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; +} |