Re: [Libguestfs] [PATCH nbdkit v2 3/4] common/utils: Add C string quoting function

eg. { '\r', '\n' } -> { '\\', 'n', '\\', 'r' } --- common/utils/utils.h | 1 + common/utils/quote.c | 58 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+) diff --git a/common/utils/utils.h b/common/utils/utils.h index 42288a5cd..1e6d8972b 100644 --- a/common/utils/utils.h +++ b/common/utils/utils.h @@ -35,6 +35,7 @@ extern void shell_quote (const char *str, FILE *fp); extern void uri_quote (const char *str, FILE *fp); +extern void c_string_quote (const char *str, FILE *fp); extern int exit_status_to_nbd_error (int status, const char *cmd); extern int set_cloexec (int fd); extern int set_nonblock (int fd); diff --git a/common/utils/quote.c b/common/utils/quote.c index 863e08a8e..877035387 100644 --- a/common/utils/quote.c +++ b/common/utils/quote.c @@ -37,6 +37,9 @@ #include <string.h> #include <unistd.h> +#include "ascii-ctype.h" +#include "hexdigit.h" + /* Print str to fp, shell quoting if necessary. This comes from * libguestfs, but was written by me so I'm relicensing it to a BSD * license for nbdkit. @@ -98,3 +101,58 @@ uri_quote (const char *str, FILE *fp) fprintf (fp, "%%%02X", str[i] & 0xff); } } + +/* Print str to fp, quoting in a way similar to C strings, for example + * '\n' -> "\n". + * + * Note that we do not emit quotes around the string, and double + * quotes within the string are not escaped. + */ +void +c_string_quote (const char *str, FILE *fp) +{ + size_t i; + char c; + + for (i = 0; c = str[i], c != '\0'; ++i) {

+ if (ascii_isprint (c)) + fputc (c, fp); + else { + switch (c) { + case '\a': + fputc ('\\', fp); + fputc ('a', fp); + break; + case '\b': + fputc ('\\', fp); + fputc ('b', fp); + break; + case '\f': + fputc ('\\', fp); + fputc ('f', fp); + break; + case '\n': + fputc ('\\', fp); + fputc ('n', fp); + break; + case '\r': + fputc ('\\', fp); + fputc ('r', fp); + break; + case '\t': + fputc ('\\', fp); + fputc ('t', fp); + break; + case '\v': + fputc ('\\', fp); + fputc ('v', fp); + break; + default: + fputc ('\\', fp); + fputc ('x', fp); + fputc (hexchar (c >> 4), fp); + fputc (hexchar (c), fp); + } + } + }

+}