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authorTavian Barnes <tavianator@tavianator.com>2023-07-13 13:30:16 -0400
committerTavian Barnes <tavianator@tavianator.com>2023-07-13 16:01:00 -0400
commit2c396fce53100cad4e472f29851f07030a80ee50 (patch)
tree4bbc7b2d313335600474b7370298a23b460ee356 /src
parente79f0d038d3ce916e744fd111b70d687f699c0bd (diff)
downloadbfs-2c396fce53100cad4e472f29851f07030a80ee50.tar.xz
bfstd: Support wordesc() without allocating
Diffstat (limited to 'src')
-rw-r--r--src/bfstd.c92
-rw-r--r--src/bfstd.h47
-rw-r--r--src/color.c20
-rw-r--r--src/diag.c29
-rw-r--r--src/diag.h4
-rw-r--r--src/dstring.c22
-rw-r--r--src/dstring.h31
7 files changed, 175 insertions, 70 deletions
diff --git a/src/bfstd.c b/src/bfstd.c
index 6f39f54..97fa3b3 100644
--- a/src/bfstd.c
+++ b/src/bfstd.c
@@ -10,6 +10,7 @@
#include <fcntl.h>
#include <langinfo.h>
#include <nl_types.h>
+#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -575,7 +576,7 @@ size_t xstrwidth(const char *str) {
}
/** Get the length of the longest printable prefix of a string. */
-static size_t printable_len(const char *str, size_t len) {
+static size_t printable_len(const char *str, size_t len, enum wesc_flags flags) {
mbstate_t mb;
memset(&mb, 0, sizeof(mb));
@@ -583,9 +584,23 @@ static size_t printable_len(const char *str, size_t len) {
while (len > 0) {
wchar_t wc;
size_t mblen = mbrtowc(&wc, cur, len, &mb);
- if (mblen == (size_t)-1 || mblen == (size_t)-2 || !iswprint(wc)) {
+ if (mblen == (size_t)-1 || mblen == (size_t)-2) {
break;
}
+
+ bool safe = iswprint(wc);
+
+ // Technically a literal newline is safe inside single quotes,
+ // but $'\n' is much nicer than '
+ // '
+ if (!(flags & WESC_SHELL) && iswspace(wc)) {
+ safe = true;
+ }
+
+ if (!safe) {
+ break;
+ }
+
cur += mblen;
len -= mblen;
}
@@ -623,13 +638,13 @@ static const char *dollar_esc(char c) {
}
/** $'Quote' a string for the shell. */
-static char *dollar_quote(char *dest, char *end, const char *str, size_t len) {
+static char *dollar_quote(char *dest, char *end, const char *str, size_t len, enum wesc_flags flags) {
static const char *hex[] = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F"};
dest = xstpecpy(dest, end, "$'");
while (len > 0) {
- size_t plen = printable_len(str, len);
+ size_t plen = printable_len(str, len, flags);
size_t elen = strcspn(str, "'\\");
size_t min = plen < elen ? plen : elen;
dest = xstpencpy(dest, end, str, min);
@@ -657,85 +672,86 @@ static char *dollar_quote(char *dest, char *end, const char *str, size_t len) {
}
/** How much of this string is safe as a bare word? */
-static size_t bare_len(const char *str) {
+static size_t bare_len(const char *str, size_t len) {
// https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_02
- return strcspn(str, "|&;<>()$`\\\"' *?[#˜=%!");
+ size_t ret = strcspn(str, "|&;<>()$`\\\"' *?[#˜=%!");
+ return ret < len ? ret : len;
}
/** How much of this string is safe to double-quote? */
-static size_t quotable_len(const char *str) {
+static size_t quotable_len(const char *str, size_t len) {
// https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_02_03
- return strcspn(str, "`$\\\"!");
+ size_t ret = strcspn(str, "`$\\\"!");
+ return ret < len ? ret : len;
}
/** "Quote" a string for the shell. */
-static char *double_quote(char *dest, char *end, const char *str) {
+static char *double_quote(char *dest, char *end, const char *str, size_t len) {
dest = xstpecpy(dest, end, "\"");
- dest = xstpecpy(dest, end, str);
+ dest = xstpencpy(dest, end, str, len);
return xstpecpy(dest, end, "\"");
}
/** 'Quote' a string for the shell. */
-static char *single_quote(char *dest, char *end, const char *str) {
+static char *single_quote(char *dest, char *end, const char *str, size_t len) {
bool open = false;
- while (*str) {
- size_t len = strcspn(str, "'");
- if (len > 0) {
+ while (len > 0) {
+ size_t chunk = strcspn(str, "'");
+ chunk = chunk < len ? chunk : len;
+ if (chunk > 0) {
if (!open) {
dest = xstpecpy(dest, end, "'");
open = true;
}
- dest = xstpencpy(dest, end, str, len);
- str += len;
+ dest = xstpencpy(dest, end, str, chunk);
+ str += chunk;
+ len -= chunk;
}
- while (*str == '\'') {
+ while (len > 0 && *str == '\'') {
if (open) {
dest = xstpecpy(dest, end, "'");
open = false;
}
dest = xstpecpy(dest, end, "\\'");
++str;
+ --len;
}
}
if (open) {
dest = xstpecpy(dest, end, "'");
}
+
return dest;
}
-char *wordesc(const char *str) {
- size_t len = strlen(str);
+char *wordesc(char *dest, char *end, const char *str, enum wesc_flags flags) {
+ return wordnesc(dest, end, str, SIZE_MAX, flags);
+}
- // Worst case: every char is replaced with $'\xXX', so at most a 7x growth
- size_t max_size = 7 * len + 3;
- char *ret = malloc(max_size);
- if (!ret) {
- return NULL;
- }
- char *cur = ret;
- char *end = ret + max_size;
+char *wordnesc(char *dest, char *end, const char *str, size_t n, enum wesc_flags flags) {
+ size_t len = strnlen(str, n);
+ char *start = dest;
- if (printable_len(str, len) < len) {
+ if (printable_len(str, len, flags) < len) {
// String contains unprintable chars, use $'this\x7Fsyntax'
- cur = dollar_quote(cur, end, str, len);
- } else if (bare_len(str) == len) {
+ dest = dollar_quote(dest, end, str, len, flags);
+ } else if (!(flags & WESC_SHELL) || bare_len(str, len) == len) {
// Whole string is safe as a bare word
- cur = xstpecpy(cur, end, str);
- } else if (quotable_len(str) == len) {
+ dest = xstpencpy(dest, end, str, len);
+ } else if (quotable_len(str, len) == len) {
// Whole string is safe to double-quote
- cur = double_quote(cur, end, str);
+ dest = double_quote(dest, end, str, len);
} else {
// Single-quote the whole string
- cur = single_quote(cur, end, str);
+ dest = single_quote(dest, end, str, len);
}
- if (cur == ret) {
- cur = xstpecpy(cur, end, "\"\"");
+ if (dest == start) {
+ dest = xstpecpy(dest, end, "\"\"");
}
- bfs_assert(cur != end, "Result truncated!");
- return ret;
+ return dest;
}
diff --git a/src/bfstd.h b/src/bfstd.h
index 832db66..fb77399 100644
--- a/src/bfstd.h
+++ b/src/bfstd.h
@@ -320,14 +320,53 @@ size_t xstrwidth(const char *str);
// #include <wordexp.h>
/**
+ * Flags for wordesc().
+ */
+enum wesc_flags {
+ /**
+ * Escape special characters so that the shell will treat the escaped
+ * string as a single word.
+ */
+ WESC_SHELL = 1 << 0,
+ /**
+ * Escape special characters so that the escaped string is safe to print
+ * to a TTY.
+ */
+ WESC_TTY = 1 << 1,
+};
+
+/**
* Escape a string as a single shell word.
*
- * @param str
+ * @param dest
+ * The destination string to fill.
+ * @param end
+ * The end of the destination buffer.
+ * @param src
+ * The string to escape.
+ * @param flags
+ * Controls which characters to escape.
+ * @return
+ * The new NUL terminator of the destination, or `end` on truncation.
+ */
+char *wordesc(char *dest, char *end, const char *str, enum wesc_flags flags);
+
+/**
+ * Escape a string as a single shell word.
+ *
+ * @param dest
+ * The destination string to fill.
+ * @param end
+ * The end of the destination buffer.
+ * @param src
* The string to escape.
+ * @param n
+ * The maximum length of the string.
+ * @param flags
+ * Controls which characters to escape.
* @return
- * A string that a shell would evaluate to str, dynamically allocated,
- * or NULL on failure.
+ * The new NUL terminator of the destination, or `end` on truncation.
*/
-char *wordesc(const char *str);
+char *wordnesc(char *dest, char *end, const char *str, size_t n, enum wesc_flags flags);
#endif // BFS_BFSTD_H
diff --git a/src/color.c b/src/color.c
index 2e039f4..0f5829f 100644
--- a/src/color.c
+++ b/src/color.c
@@ -16,6 +16,7 @@
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
+#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -891,6 +892,11 @@ static int print_reset(CFILE *cfile) {
}
}
+/** Print a shell-escaped string. */
+static int print_wordesc(CFILE *cfile, const char *str, size_t n, enum wesc_flags flags) {
+ return dstrnescat(&cfile->buffer, str, n, flags);
+}
+
/** Print a string with an optional color. */
static int print_colored(CFILE *cfile, const struct esc_seq *esc, const char *str, size_t len) {
if (print_esc(cfile, esc) != 0) {
@@ -1069,18 +1075,6 @@ static int print_link_target(CFILE *cfile, const struct BFTW *ftwbuf) {
return ret;
}
-/** Print an shell-escaped string. */
-static int print_wordesc(CFILE *cfile, const char *str) {
- char *esc = wordesc(str);
- if (!esc) {
- return -1;
- }
-
- int ret = dstrcat(&cfile->buffer, esc);
- free(esc);
- return ret;
-}
-
/** Format some colored output to the buffer. */
BFS_FORMATTER(2, 3)
static int cbuff(CFILE *cfile, const char *format, ...);
@@ -1224,7 +1218,7 @@ static int cvbuff(CFILE *cfile, const char *format, va_list args) {
case 'p':
switch (*++i) {
case 'q':
- if (print_wordesc(cfile, va_arg(args, const char *)) != 0) {
+ if (print_wordesc(cfile, va_arg(args, const char *), SIZE_MAX, WESC_SHELL | WESC_TTY) != 0) {
return -1;
}
break;
diff --git a/src/diag.c b/src/diag.c
index acea9ad..0590847 100644
--- a/src/diag.c
+++ b/src/diag.c
@@ -2,6 +2,7 @@
// SPDX-License-Identifier: 0BSD
#include "diag.h"
+#include "alloc.h"
#include "bfstd.h"
#include "ctx.h"
#include "color.h"
@@ -114,7 +115,7 @@ bool bfs_debug_prefix(const struct bfs_ctx *ctx, enum debug_flags flag) {
}
/** Recursive part of highlight_expr(). */
-static bool highlight_expr_recursive(const struct bfs_ctx *ctx, const struct bfs_expr *expr, bool *args) {
+static bool highlight_expr_recursive(const struct bfs_ctx *ctx, const struct bfs_expr *expr, bool args[]) {
if (!expr) {
return false;
}
@@ -141,7 +142,7 @@ static bool highlight_expr_recursive(const struct bfs_ctx *ctx, const struct bfs
}
/** Highlight an expression in the command line. */
-static bool highlight_expr(const struct bfs_ctx *ctx, const struct bfs_expr *expr, bool *args) {
+static bool highlight_expr(const struct bfs_ctx *ctx, const struct bfs_expr *expr, bool args[]) {
for (size_t i = 0; i < ctx->argc; ++i) {
args[i] = false;
}
@@ -150,21 +151,21 @@ static bool highlight_expr(const struct bfs_ctx *ctx, const struct bfs_expr *exp
}
/** Print a highlighted portion of the command line. */
-static void bfs_argv_diag(const struct bfs_ctx *ctx, const bool *args, bool warning) {
+static void bfs_argv_diag(const struct bfs_ctx *ctx, const bool args[], bool warning) {
if (warning) {
bfs_warning_prefix(ctx);
} else {
bfs_error_prefix(ctx);
}
- char *argv[ctx->argc];
+ char **argv = ZALLOC_ARRAY(char *, ctx->argc);
+ if (!argv) {
+ return;
+ }
+
for (size_t i = 0; i < ctx->argc; ++i) {
- argv[i] = wordesc(ctx->argv[i]);
- if (!argv[i]) {
- for (size_t j = 0; j < i; ++j) {
- free(argv[j]);
- }
- return;
+ if (dstrescat(&argv[i], ctx->argv[i], WESC_SHELL | WESC_TTY) != 0) {
+ goto done;
}
}
@@ -223,12 +224,14 @@ static void bfs_argv_diag(const struct bfs_ctx *ctx, const bool *args, bool warn
cfprintf(ctx->cerr, "\n");
+done:
for (size_t i = 0; i < ctx->argc; ++i) {
- free(argv[i]);
+ dstrfree(argv[i]);
}
+ free(argv);
}
-void bfs_argv_error(const struct bfs_ctx *ctx, const bool *args) {
+void bfs_argv_error(const struct bfs_ctx *ctx, const bool args[]) {
bfs_argv_diag(ctx, args, false);
}
@@ -239,7 +242,7 @@ void bfs_expr_error(const struct bfs_ctx *ctx, const struct bfs_expr *expr) {
}
}
-bool bfs_argv_warning(const struct bfs_ctx *ctx, const bool *args) {
+bool bfs_argv_warning(const struct bfs_ctx *ctx, const bool args[]) {
if (!ctx->warn) {
return false;
}
diff --git a/src/diag.h b/src/diag.h
index c909da5..e019db0 100644
--- a/src/diag.h
+++ b/src/diag.h
@@ -149,7 +149,7 @@ bool bfs_debug_prefix(const struct bfs_ctx *ctx, enum debug_flags flag);
/**
* Highlight parts of the command line in an error message.
*/
-void bfs_argv_error(const struct bfs_ctx *ctx, const bool *args);
+void bfs_argv_error(const struct bfs_ctx *ctx, const bool args[]);
/**
* Highlight parts of an expression in an error message.
@@ -159,7 +159,7 @@ void bfs_expr_error(const struct bfs_ctx *ctx, const struct bfs_expr *expr);
/**
* Highlight parts of the command line in a warning message.
*/
-bool bfs_argv_warning(const struct bfs_ctx *ctx, const bool *args);
+bool bfs_argv_warning(const struct bfs_ctx *ctx, const bool args[]);
/**
* Highlight parts of an expression in a warning message.
diff --git a/src/dstring.c b/src/dstring.c
index dada70b..60a7df9 100644
--- a/src/dstring.c
+++ b/src/dstring.c
@@ -232,6 +232,28 @@ fail:
return -1;
}
+int dstrescat(char **dest, const char *str, enum wesc_flags flags) {
+ return dstrnescat(dest, str, SIZE_MAX, flags);
+}
+
+int dstrnescat(char **dest, const char *str, size_t n, enum wesc_flags flags) {
+ size_t len = *dest ? dstrlen(*dest) : 0;
+
+ // Worst case growth is `ccc...` => $'\xCC\xCC\xCC...'
+ n = strnlen(str, n);
+ size_t cap = len + 4 * n + 3;
+ if (dstreserve(dest, cap) != 0) {
+ return -1;
+ }
+
+ char *cur = *dest + len;
+ char *end = *dest + cap + 1;
+ cur = wordnesc(cur, end, str, n, flags);
+ bfs_assert(cur != end, "wordesc() result truncated");
+
+ return dstresize(dest, cur - *dest);
+}
+
void dstrfree(char *dstr) {
if (dstr) {
free(dstrheader(dstr));
diff --git a/src/dstring.h b/src/dstring.h
index 2673f1b..88ca79f 100644
--- a/src/dstring.h
+++ b/src/dstring.h
@@ -8,6 +8,7 @@
#ifndef BFS_DSTRING_H
#define BFS_DSTRING_H
+#include "bfstd.h"
#include "config.h"
#include <stdarg.h>
#include <stddef.h>
@@ -262,6 +263,36 @@ BFS_FORMATTER(2, 0)
int dstrvcatf(char **str, const char *format, va_list args);
/**
+ * Concatenate while shell-escaping.
+ *
+ * @param dest
+ * The destination dynamic string.
+ * @param str
+ * The string to escape.
+ * @param flags
+ * Flags for wordesc().
+ * @return
+ * 0 on success, -1 on failure.
+ */
+int dstrescat(char **dest, const char *str, enum wesc_flags flags);
+
+/**
+ * Concatenate while shell-escaping.
+ *
+ * @param dest
+ * The destination dynamic string.
+ * @param str
+ * The string to escape.
+ * @param n
+ * The maximum length of the string.
+ * @param flags
+ * Flags for wordesc().
+ * @return
+ * 0 on success, -1 on failure.
+ */
+int dstrnescat(char **dest, const char *str, size_t n, enum wesc_flags flags);
+
+/**
* Free a dynamic string.
*
* @param dstr