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Implement -e option to echo (to interpret special characters), and -E to not interpret them

Browse source 
https://github.com/fish-shell/fish-shell/issues/337
This commit is contained in:
ridiculousfish 2012-10-17 02:56:03 -07:00
parent 469743cd23
commit 7ee0ce745e
3 changed files with 174 additions and 6 deletions
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152
builtin.cpp
View file

@ -1463,6 +1463,86 @@ static int builtin_functions( parser_t &parser, wchar_t **argv )
return res;
}
static unsigned int builtin_echo_octal_digit(wchar_t wc)
{
switch (wc)
{
case L'0': return 0;
case L'1': return 1;
case L'2': return 2;
case L'3': return 3;
case L'4': return 4;
case L'5': return 5;
case L'6': return 6;
case L'7': return 7;
default: return UINT_MAX;
}
}
static unsigned int builtin_echo_hex_digit(wchar_t wc)
{
switch (wc)
{
case L'a': case L'A': return 10;
case L'b': case L'B': return 11;
case L'c': case L'C': return 12;
case L'd': case L'D': return 13;
case L'e': case L'E': return 14;
case L'f': case L'F': return 15;
default: return builtin_echo_octal_digit(wc);
}
}
/* Parse a numeric escape sequence in str, returning whether we succeeded.
Also return the number of characters consumed and the resulting value.
Supported escape sequences:
\0nnn: octal value, zero to three digits
\nnn: octal value, one to three digits
\xhh: hex value, one to two digits
*/
static bool builtin_echo_parse_numeric_sequence(const wchar_t *str, size_t *consumed, unsigned char *out_val)
{
bool success = false;
unsigned char val = 0;
size_t idx = 0;
if (builtin_echo_octal_digit(str[0]) != UINT_MAX)
{
// If the first digit is a 0, we allow four digits (including that zero)
// Otherwise we allow 3.
unsigned int max_digits = (str[0] == L'0' ? 4 : 3);
for (idx = 0; idx < max_digits; idx++)
{
unsigned int digit = builtin_echo_octal_digit(str[idx]);
if (digit == UINT_MAX)
break;
val = val * 8 + digit;
}
// Can't fail, since we know we had at least one octal digit at str[1]
success = true;
}
else if (str[0] == L'x')
{
// Hex escape
for (idx = 1; idx < 3; idx++)
{
unsigned int digit = builtin_echo_hex_digit(str[idx]);
if (digit == UINT_MAX)
break;
val = val * 16 + digit;
}
// Requires at least one digit
success = (idx > 1);
}
if (success)
{
*consumed = idx;
*out_val = val;
}
return success;
}
/** The echo builtin.
bash only respects -n if it's the first argument. We'll do the same.
We also support a new option -s to mean "no spaces"
@ -1475,23 +1555,83 @@ static int builtin_echo( parser_t &parser, wchar_t **argv )
return STATUS_BUILTIN_ERROR;
/* Process options */
bool print_newline = true, print_spaces = true;
bool print_newline = true, print_spaces = true, interpret_special_chars = false;
while (*argv) {
if (! wcscmp(*argv, L"-n")) {
print_newline = false;
argv++;
} else if (! wcscmp(*argv, L"-s")) {
print_spaces = false;
argv++;
} else if (! wcscmp(*argv, L"-e")) {
interpret_special_chars = true;
} else if (! wcscmp(*argv, L"-E")) {
interpret_special_chars = false;
} else {
break;
}
argv++;
}
for (size_t idx = 0; argv[idx]; idx++) {
/* The special character \c can be used to indicate no more output */
bool continue_output = true;
for (size_t idx = 0; continue_output && argv[idx] != NULL; idx++) {
if (print_spaces && idx > 0)
stdout_buffer.push_back(' ');
stdout_buffer.append(argv[idx]);
const wchar_t *str = argv[idx];
for (size_t j=0; continue_output && str[j]; j++)
{
if (! interpret_special_chars || str[j] != L'\\')
{
/* Not an escape */
stdout_buffer.push_back(str[j]);
}
else
{
/* Most escapes consume one character in addition to the backslash; the numeric sequences may consume more, while an unrecognized escape sequence consumes none. */
wchar_t wc;
size_t consumed = 1;
switch (str[j+1])
{
case L'a': wc = L'\a'; break;
case L'b': wc = L'\b'; break;
case L'e': wc = L'\e'; break;
case L'f': wc = L'\f'; break;
case L'n': wc = L'\n'; break;
case L'r': wc = L'\r'; break;
case L't': wc = L'\t'; break;
case L'v': wc = L'\v'; break;
case L'\\': wc = L'\\'; break;
case L'c': wc = 0; continue_output = false; break;
default:
{
/* Octal and hex escape sequences */
unsigned char narrow_val = 0;
if (builtin_echo_parse_numeric_sequence(str + j + 1, &consumed, &narrow_val))
{
/* Here consumed must have been set to something */
wc = narrow_val; //is this OK for conversion?
}
else
{
/* Not a recognized escape. We consume only the backslash. */
wc = L'\\';
consumed = 0;
}
break;
}
}
/* Skip over characters that were part of this escape sequence (but not the backslash, which will be handled by the loop increment */
j += consumed;
if (continue_output)
stdout_buffer.push_back(wc);
}
}
}
if (print_newline)
stdout_buffer.push_back('\n');

16
tests/test1.in
View file

@ -73,3 +73,19 @@ else
set sta fail
end
echo Test 5 $sta
# echo tests
echo 'abc\ndef'
echo -e 'abc\ndef'
echo -e 'abc\zdef'
echo -e 'abc\41def'
echo -e 'abc\041def'
echo -e 'abc\121def'
echo -e 'abc\1212def'
echo -e 'abc\cdef'
echo -e Catch your breath
echo -e 'abc\x21def'
echo -e 'abc\x211def'

12
tests/test1.out
View file

@ -7,3 +7,15 @@ Test pass
Test 3 pass
Test 4 pass
Test 5 pass
abc\ndef
abc
def
abc\zdef
abc!def
abc!def
abcQdef
abcQ2def
abc
Catch your breath
abc!def
abc!1def