MINOR: tools: add new functions to quote-encode strings
qstr() and cstr() will be used to quote-encode strings. The first one
does it unconditionally. The second one is aimed at CSV files where the
quote-encoding is only needed when the field contains a quote or a comma.
diff --git a/include/common/standard.h b/include/common/standard.h
index ecac1e0..8811c6f 100644
--- a/include/common/standard.h
+++ b/include/common/standard.h
@@ -52,6 +52,10 @@
/* number of itoa_str entries */
#define NB_ITOA_STR 10
+/* maximum quoted string length (truncated above) */
+#define QSTR_SIZE 200
+#define NB_QSTR 10
+
/****** string-specific macros and functions ******/
/* if a > max, then bound <a> to <max>. The macro returns the new <a> */
#define UBOUND(a, max) ({ typeof(a) b = (max); if ((a) > b) (a) = b; (a); })
@@ -195,6 +199,29 @@
return ret;
}
+/* returns a locally allocated string containing the quoted encoding of the
+ * input string. The output may be truncated to QSTR_SIZE chars, but it is
+ * guaranteed that the string will always be properly terminated. Quotes are
+ * encoded by doubling them as is commonly done in CSV files. QSTR_SIZE must
+ * always be at least 4 chars.
+ */
+const char *qstr(const char *str);
+
+/* returns <str> or its quote-encoded equivalent if it contains at least one
+ * quote or a comma. This is aimed at build CSV-compatible strings.
+ */
+static inline const char *cstr(const char *str)
+{
+ const char *p = str;
+
+ while (*p) {
+ if (*p == ',' || *p == '"')
+ return qstr(str);
+ p++;
+ }
+ return str;
+}
+
/*
* Returns non-zero if character <s> is a hex digit (0-9, a-f, A-F), else zero.
*/
diff --git a/src/standard.c b/src/standard.c
index b0c5fe6..f57724c 100644
--- a/src/standard.c
+++ b/src/standard.c
@@ -38,6 +38,12 @@
char itoa_str[NB_ITOA_STR][171];
int itoa_idx = 0; /* index of next itoa_str to use */
+/* sometimes we'll need to quote strings (eg: in stats), and we don't expect
+ * to quote strings larger than a max configuration line.
+ */
+char quoted_str[NB_QSTR][QSTR_SIZE + 1];
+int quoted_idx = 0;
+
/*
* unsigned long long ASCII representation
*
@@ -444,6 +450,39 @@
return (n) ? ultoa_r(n, buffer, size) : (alt ? alt : "");
}
+/* returns a locally allocated string containing the quoted encoding of the
+ * input string. The output may be truncated to QSTR_SIZE chars, but it is
+ * guaranteed that the string will always be properly terminated. Quotes are
+ * encoded by doubling them as is commonly done in CSV files. QSTR_SIZE must
+ * always be at least 4 chars.
+ */
+const char *qstr(const char *str)
+{
+ char *ret = quoted_str[quoted_idx];
+ char *p, *end;
+
+ if (++quoted_idx >= NB_QSTR)
+ quoted_idx = 0;
+
+ p = ret;
+ end = ret + QSTR_SIZE;
+
+ *p++ = '"';
+
+ /* always keep 3 chars to support passing "" and the ending " */
+ while (*str && p < end - 3) {
+ if (*str == '"') {
+ *p++ = '"';
+ *p++ = '"';
+ }
+ else
+ *p++ = *str;
+ str++;
+ }
+ *p++ = '"';
+ return ret;
+}
+
/*
* Returns non-zero if character <s> is a hex digit (0-9, a-f, A-F), else zero.
*