From 8409f688589c41ac30a1d67f41b3ffab6ae175d3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= Date: Thu, 17 May 2018 10:55:21 +0200 Subject: [PATCH] basic/string-util: add a convenience function to cescape mostly-ascii fields MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It's not supposed to be the most efficient, but instead fast and simple to use. I kept the logic in ellipsize_mem() to use unicode ellipsis even in non-unicode locales. I'm not quite convinced things should be this way, especially that with this patch it'd actually be simpler to always use "…" in unicode locale and "..." otherwise, but Lennart wanted it this way for some reason. --- src/basic/string-util.c | 70 ++++++++++++++++++++++++++++--------- src/basic/string-util.h | 1 + src/test/test-string-util.c | 25 +++++++++++++ 3 files changed, 80 insertions(+), 16 deletions(-) diff --git a/src/basic/string-util.c b/src/basic/string-util.c index 07c9938a3f..b06b50397e 100644 --- a/src/basic/string-util.c +++ b/src/basic/string-util.c @@ -14,6 +14,7 @@ #include #include "alloc-util.h" +#include "escape.h" #include "gunicode.h" #include "locale-util.h" #include "macro.h" @@ -453,6 +454,20 @@ bool string_has_cc(const char *p, const char *ok) { return false; } +static int write_ellipsis(char *buf, bool unicode) { + if (unicode || is_locale_utf8()) { + buf[0] = 0xe2; /* tri-dot ellipsis: … */ + buf[1] = 0x80; + buf[2] = 0xa6; + } else { + buf[0] = '.'; + buf[1] = '.'; + buf[2] = '.'; + } + + return 3; +} + static char *ascii_ellipsize_mem(const char *s, size_t old_length, size_t new_length, unsigned percent) { size_t x, need_space; char *r; @@ -501,17 +516,7 @@ static char *ascii_ellipsize_mem(const char *s, size_t old_length, size_t new_le assert(x <= new_length - need_space); memcpy(r, s, x); - - if (is_locale_utf8()) { - r[x+0] = 0xe2; /* tri-dot ellipsis: … */ - r[x+1] = 0x80; - r[x+2] = 0xa6; - } else { - r[x+0] = '.'; - r[x+1] = '.'; - r[x+2] = '.'; - } - + write_ellipsis(r + x, false); memcpy(r + x + 3, s + old_length - (new_length - x - need_space), new_length - x - need_space + 1); @@ -596,23 +601,56 @@ char *ellipsize_mem(const char *s, size_t old_length, size_t new_length, unsigne */ memcpy(e, s, len); - e[len + 0] = 0xe2; /* tri-dot ellipsis: … */ - e[len + 1] = 0x80; - e[len + 2] = 0xa6; - + write_ellipsis(e + len, true); memcpy(e + len + 3, j, len2 + 1); return e; } char *ellipsize(const char *s, size_t length, unsigned percent) { - if (length == (size_t) -1) return strdup(s); return ellipsize_mem(s, strlen(s), length, percent); } +char *cellescape(char *buf, size_t len, const char *s) { + /* Escape and ellipsize s into buffer buf of size len. Only non-control ASCII + * characters are copied as they are, everything else is escaped. The result + * is different then if escaping and ellipsization was performed in two + * separate steps, because each sequence is either stored in full or skipped. + * + * This function should be used for logging about strings which expected to + * be plain ASCII in a safe way. + * + * An ellipsis will be used if s is too long. It was always placed at the + * very end. + */ + + size_t i; + const char *t = s; + + assert(len > 4 + 4 + 1); /* two chars and the terminator */ + + for (i = 0; i < len - 9; t++) { + if (!*t) + goto done; + i += cescape_char(*t, buf + i); + } + + /* We have space for one more char and terminating nul at this point */ + if (*t) { + if (*(t+1)) + i += write_ellipsis(buf + i, false); + else + i += cescape_char(*t, buf + i); + } + + done: + buf[i] = '\0'; + return buf; +} + bool nulstr_contains(const char *nulstr, const char *needle) { const char *i; diff --git a/src/basic/string-util.h b/src/basic/string-util.h index aa00724266..3c5e2a9ef6 100644 --- a/src/basic/string-util.h +++ b/src/basic/string-util.h @@ -157,6 +157,7 @@ bool string_has_cc(const char *p, const char *ok) _pure_; char *ellipsize_mem(const char *s, size_t old_length_bytes, size_t new_length_columns, unsigned percent); char *ellipsize(const char *s, size_t length, unsigned percent); +char *cellescape(char *buf, size_t len, const char *s); bool nulstr_contains(const char *nulstr, const char *needle); diff --git a/src/test/test-string-util.c b/src/test/test-string-util.c index eac12ac7af..413adfda7d 100644 --- a/src/test/test-string-util.c +++ b/src/test/test-string-util.c @@ -6,6 +6,7 @@ ***/ #include "alloc-util.h" +#include "locale-util.h" #include "macro.h" #include "string-util.h" #include "strv.h" @@ -77,6 +78,29 @@ static void test_ascii_strcasecmp_nn(void) { assert_se(ascii_strcasecmp_nn("BBbb", 4, "aaaa", 4) > 0); } +static void test_cellescape(void) { + char buf[40]; + + assert_se(streq(cellescape(buf, 10, "1"), "1")); + assert_se(streq(cellescape(buf, 10, "12"), "12")); + assert_se(streq(cellescape(buf, 10, "123"), is_locale_utf8() ? "1…" : "1...")); + + assert_se(streq(cellescape(buf, 10, "1\011"), "1\\t")); + assert_se(streq(cellescape(buf, 10, "1\020"), "1\\020")); + assert_se(streq(cellescape(buf, 10, "1\020x"), is_locale_utf8() ? "1…" : "1...")); + + assert_se(streq(cellescape(buf, 40, "1\020"), "1\\020")); + assert_se(streq(cellescape(buf, 40, "1\020x"), "1\\020x")); + + assert_se(streq(cellescape(buf, 40, "\a\b\f\n\r\t\v\\\"'"), "\\a\\b\\f\\n\\r\\t\\v\\\\\\\"\\'")); + assert_se(streq(cellescape(buf, 10, "\a\b\f\n\r\t\v\\\"'"), is_locale_utf8() ? "\\a…" : "\\a...")); + assert_se(streq(cellescape(buf, 11, "\a\b\f\n\r\t\v\\\"'"), is_locale_utf8() ? "\\a…" : "\\a...")); + assert_se(streq(cellescape(buf, 12, "\a\b\f\n\r\t\v\\\"'"), is_locale_utf8() ? "\\a\\b…" : "\\a\\b...")); + + assert_se(streq(cellescape(buf, sizeof buf, "1\020"), "1\\020")); + assert_se(streq(cellescape(buf, sizeof buf, "1\020x"), "1\\020x")); +} + static void test_streq_ptr(void) { assert_se(streq_ptr(NULL, NULL)); assert_se(!streq_ptr("abc", "cdef")); @@ -422,6 +446,7 @@ int main(int argc, char *argv[]) { test_string_erase(); test_ascii_strcasecmp_n(); test_ascii_strcasecmp_nn(); + test_cellescape(); test_streq_ptr(); test_strstrip(); test_strextend();