Why doesn't the tilde (~) expand inside double quotes?
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According to this answer and my own understanding, the tilde expands to the home directory:
$ echo ~
/home/braiam
Now, whenever I want the shell expansion to work, i. e. using variable names such $FOO
, and do not break due unexpected characters, such spaces, etc. one should use double quotes "
:
$ FOO="some string with spaces"
$ BAR="echo $FOO"
$ echo $BAR
echo some string with spaces
Why doesn't this expansion works with the tilde?
$ echo ~/some/path
/home/braiam/some/path
$ echo "~/some/path"
~/some/path
shell
add a comment |
According to this answer and my own understanding, the tilde expands to the home directory:
$ echo ~
/home/braiam
Now, whenever I want the shell expansion to work, i. e. using variable names such $FOO
, and do not break due unexpected characters, such spaces, etc. one should use double quotes "
:
$ FOO="some string with spaces"
$ BAR="echo $FOO"
$ echo $BAR
echo some string with spaces
Why doesn't this expansion works with the tilde?
$ echo ~/some/path
/home/braiam/some/path
$ echo "~/some/path"
~/some/path
shell
1
pubs.opengroup.org/onlinepubs/009695399/utilities/…
– llua
Aug 24 '14 at 1:12
3
Also note that this has the inconsistency when providing a program argument on command line that on command argument--path ~/myfile
expands but--path=~/myfile
doesn't.
– Ángel
Aug 24 '14 at 18:59
Related: Does ~ always equal $HOME
– Stéphane Chazelas
Aug 18 '16 at 10:41
Related (on Ask Ubuntu): Why does mkdir fail (no such file or directory) in a script with BIN_DIR=“~/bin/”?
– Eliah Kagan
Nov 17 '17 at 12:49
A variation on this theme is unix.stackexchange.com/questions/279565 .
– JdeBP
Jan 26 '18 at 16:38
add a comment |
According to this answer and my own understanding, the tilde expands to the home directory:
$ echo ~
/home/braiam
Now, whenever I want the shell expansion to work, i. e. using variable names such $FOO
, and do not break due unexpected characters, such spaces, etc. one should use double quotes "
:
$ FOO="some string with spaces"
$ BAR="echo $FOO"
$ echo $BAR
echo some string with spaces
Why doesn't this expansion works with the tilde?
$ echo ~/some/path
/home/braiam/some/path
$ echo "~/some/path"
~/some/path
shell
According to this answer and my own understanding, the tilde expands to the home directory:
$ echo ~
/home/braiam
Now, whenever I want the shell expansion to work, i. e. using variable names such $FOO
, and do not break due unexpected characters, such spaces, etc. one should use double quotes "
:
$ FOO="some string with spaces"
$ BAR="echo $FOO"
$ echo $BAR
echo some string with spaces
Why doesn't this expansion works with the tilde?
$ echo ~/some/path
/home/braiam/some/path
$ echo "~/some/path"
~/some/path
shell
shell
edited Oct 13 '17 at 2:22
Reid
24849
24849
asked Aug 24 '14 at 0:57
BraiamBraiam
23.8k2077142
23.8k2077142
1
pubs.opengroup.org/onlinepubs/009695399/utilities/…
– llua
Aug 24 '14 at 1:12
3
Also note that this has the inconsistency when providing a program argument on command line that on command argument--path ~/myfile
expands but--path=~/myfile
doesn't.
– Ángel
Aug 24 '14 at 18:59
Related: Does ~ always equal $HOME
– Stéphane Chazelas
Aug 18 '16 at 10:41
Related (on Ask Ubuntu): Why does mkdir fail (no such file or directory) in a script with BIN_DIR=“~/bin/”?
– Eliah Kagan
Nov 17 '17 at 12:49
A variation on this theme is unix.stackexchange.com/questions/279565 .
– JdeBP
Jan 26 '18 at 16:38
add a comment |
1
pubs.opengroup.org/onlinepubs/009695399/utilities/…
– llua
Aug 24 '14 at 1:12
3
Also note that this has the inconsistency when providing a program argument on command line that on command argument--path ~/myfile
expands but--path=~/myfile
doesn't.
– Ángel
Aug 24 '14 at 18:59
Related: Does ~ always equal $HOME
– Stéphane Chazelas
Aug 18 '16 at 10:41
Related (on Ask Ubuntu): Why does mkdir fail (no such file or directory) in a script with BIN_DIR=“~/bin/”?
– Eliah Kagan
Nov 17 '17 at 12:49
A variation on this theme is unix.stackexchange.com/questions/279565 .
– JdeBP
Jan 26 '18 at 16:38
1
1
pubs.opengroup.org/onlinepubs/009695399/utilities/…
– llua
Aug 24 '14 at 1:12
pubs.opengroup.org/onlinepubs/009695399/utilities/…
– llua
Aug 24 '14 at 1:12
3
3
Also note that this has the inconsistency when providing a program argument on command line that on command argument
--path ~/myfile
expands but --path=~/myfile
doesn't.– Ángel
Aug 24 '14 at 18:59
Also note that this has the inconsistency when providing a program argument on command line that on command argument
--path ~/myfile
expands but --path=~/myfile
doesn't.– Ángel
Aug 24 '14 at 18:59
Related: Does ~ always equal $HOME
– Stéphane Chazelas
Aug 18 '16 at 10:41
Related: Does ~ always equal $HOME
– Stéphane Chazelas
Aug 18 '16 at 10:41
Related (on Ask Ubuntu): Why does mkdir fail (no such file or directory) in a script with BIN_DIR=“~/bin/”?
– Eliah Kagan
Nov 17 '17 at 12:49
Related (on Ask Ubuntu): Why does mkdir fail (no such file or directory) in a script with BIN_DIR=“~/bin/”?
– Eliah Kagan
Nov 17 '17 at 12:49
A variation on this theme is unix.stackexchange.com/questions/279565 .
– JdeBP
Jan 26 '18 at 16:38
A variation on this theme is unix.stackexchange.com/questions/279565 .
– JdeBP
Jan 26 '18 at 16:38
add a comment |
4 Answers
4
active
oldest
votes
The reason, because inside double quotes, tilde ~
has no special meaning, it's treated as literal.
POSIX defines Double-Quotes as:
Enclosing characters in double-quotes ( "" ) shall preserve the
literal value of all characters within the double-quotes, with the
exception of the characters dollar sign, backquote, and backslash,
...
The application shall ensure that a double-quote is preceded by a
backslash to be included within double-quotes. The parameter '@' has
special meaning inside double-quotes
Except $, `, and @, others characters are treated as literal inside double quotes.
9
In which case I guess you should use$HOME
.
– Seth
Aug 24 '14 at 20:29
11
Or you can just not quote the~
, for examplels -l ~/"My Documents"
– Andrew Medico
Aug 24 '14 at 21:47
This is very non-intuitive. What is the reason they chose to do this? (This answer doesn't actually give the reason, but rather just points to the standard, but presumably the standard was written that way for a reason.)
– iconoclast
Jan 16 '15 at 2:56
1
@iconoclast if you really want a "why they got implemented this way" read Stephane answer instead.
– Braiam
Mar 8 '15 at 16:46
2
So, @iconoclast, why is the sky blue? :) :) :)
– Jesse Chisholm
Mar 28 '16 at 18:10
|
show 3 more comments
Tilde expansion is defined by POSIX as:
A "tilde-prefix" consists of an unquoted <tilde> character at the beginning of a word, followed by all of the characters preceding the first unquoted <slash> in the word, or all the characters in the word if there is no <slash>. In an assignment, multiple tilde-prefixes can be used: [...] following the <equals-sign> of the assignment, following any unquoted <colon>, or both. [...] If none of the characters in the tilde-prefix are quoted, the characters in the tilde-prefix following the <tilde> are treated as a possible login name from the user database. [...] If the login name is null (that is, the tilde-prefix contains only the tilde), the tilde-prefix is replaced by the value of the variable HOME. If HOME is unset, the results are unspecified. [...]
So the shortest answer is "because it's defined that way": quoting any of the characters in the prefix, including the ~
, suppresses expansion.
It also defines the expansion as always resulting in a single word, so quoting would be unnecessary:
The pathname resulting from tilde expansion shall be treated as if quoted to prevent it being altered by field splitting and pathname expansion.
Where some of the path requires quoting, but the rest is a tilde prefix, you can combine tilde expansion and ordinary quoting straightforwardly:
$ cat ~/"file name with spaces"
On the broader "why": since there's no conceivable use for word-splitting ~
, that should be the default behaviour, rather than requiring it to be quoted. Because there's no need to quote it, giving ~
a special meaning inside quotes would be an unnecessary complication. And, of course, historical reasons mean it couldn't be changed now even if that were desirable.
According to this bash guide, tilde expansion happens before whitespace separation. Is there a way to safely do a tilde expansion, even if you home directory has whitespace in it? Ordinarily, of course, you'd do this sort of thing with""
.
– Lucretiel
Aug 21 '15 at 18:53
The expansion is a single word; see the second quoted passage in the answer.
– Michael Homer
Aug 21 '15 at 20:38
add a comment |
~
originates in the C-shell, long before it was added to the Korn shell and later added to the POSIX shell specification.
In the C-shell, ~
was a globbing operator (expanded by the same routine as the one expanding *.txt
for instance), so like the rest of the globbing was not performed inside double quotes.
add a comment |
While this doesn't answer why it's designed that way, you use $HOME
instead if you need to substitute, since that's essentially what ~
does.
$ echo "$HOME/some/path"
/home/braiam/some/path
6
this doesn't work with~otheruser
– Johannes Kuhn
Aug 24 '14 at 10:41
2
True, but you could do: THEM=~otheruser then use "$THEM/some/path"
– melds
Sep 1 '14 at 6:27
1
The workaround for~otheruser
shows what a bad idea it was to treat~
differently than variables and other things that are expanded inside double quotes.
– iconoclast
Jan 16 '15 at 2:59
add a comment |
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4 Answers
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active
oldest
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4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
The reason, because inside double quotes, tilde ~
has no special meaning, it's treated as literal.
POSIX defines Double-Quotes as:
Enclosing characters in double-quotes ( "" ) shall preserve the
literal value of all characters within the double-quotes, with the
exception of the characters dollar sign, backquote, and backslash,
...
The application shall ensure that a double-quote is preceded by a
backslash to be included within double-quotes. The parameter '@' has
special meaning inside double-quotes
Except $, `, and @, others characters are treated as literal inside double quotes.
9
In which case I guess you should use$HOME
.
– Seth
Aug 24 '14 at 20:29
11
Or you can just not quote the~
, for examplels -l ~/"My Documents"
– Andrew Medico
Aug 24 '14 at 21:47
This is very non-intuitive. What is the reason they chose to do this? (This answer doesn't actually give the reason, but rather just points to the standard, but presumably the standard was written that way for a reason.)
– iconoclast
Jan 16 '15 at 2:56
1
@iconoclast if you really want a "why they got implemented this way" read Stephane answer instead.
– Braiam
Mar 8 '15 at 16:46
2
So, @iconoclast, why is the sky blue? :) :) :)
– Jesse Chisholm
Mar 28 '16 at 18:10
|
show 3 more comments
The reason, because inside double quotes, tilde ~
has no special meaning, it's treated as literal.
POSIX defines Double-Quotes as:
Enclosing characters in double-quotes ( "" ) shall preserve the
literal value of all characters within the double-quotes, with the
exception of the characters dollar sign, backquote, and backslash,
...
The application shall ensure that a double-quote is preceded by a
backslash to be included within double-quotes. The parameter '@' has
special meaning inside double-quotes
Except $, `, and @, others characters are treated as literal inside double quotes.
9
In which case I guess you should use$HOME
.
– Seth
Aug 24 '14 at 20:29
11
Or you can just not quote the~
, for examplels -l ~/"My Documents"
– Andrew Medico
Aug 24 '14 at 21:47
This is very non-intuitive. What is the reason they chose to do this? (This answer doesn't actually give the reason, but rather just points to the standard, but presumably the standard was written that way for a reason.)
– iconoclast
Jan 16 '15 at 2:56
1
@iconoclast if you really want a "why they got implemented this way" read Stephane answer instead.
– Braiam
Mar 8 '15 at 16:46
2
So, @iconoclast, why is the sky blue? :) :) :)
– Jesse Chisholm
Mar 28 '16 at 18:10
|
show 3 more comments
The reason, because inside double quotes, tilde ~
has no special meaning, it's treated as literal.
POSIX defines Double-Quotes as:
Enclosing characters in double-quotes ( "" ) shall preserve the
literal value of all characters within the double-quotes, with the
exception of the characters dollar sign, backquote, and backslash,
...
The application shall ensure that a double-quote is preceded by a
backslash to be included within double-quotes. The parameter '@' has
special meaning inside double-quotes
Except $, `, and @, others characters are treated as literal inside double quotes.
The reason, because inside double quotes, tilde ~
has no special meaning, it's treated as literal.
POSIX defines Double-Quotes as:
Enclosing characters in double-quotes ( "" ) shall preserve the
literal value of all characters within the double-quotes, with the
exception of the characters dollar sign, backquote, and backslash,
...
The application shall ensure that a double-quote is preceded by a
backslash to be included within double-quotes. The parameter '@' has
special meaning inside double-quotes
Except $, `, and @, others characters are treated as literal inside double quotes.
edited Aug 24 '14 at 20:27
Lucio
5491816
5491816
answered Aug 24 '14 at 5:09
cuonglmcuonglm
106k25211308
106k25211308
9
In which case I guess you should use$HOME
.
– Seth
Aug 24 '14 at 20:29
11
Or you can just not quote the~
, for examplels -l ~/"My Documents"
– Andrew Medico
Aug 24 '14 at 21:47
This is very non-intuitive. What is the reason they chose to do this? (This answer doesn't actually give the reason, but rather just points to the standard, but presumably the standard was written that way for a reason.)
– iconoclast
Jan 16 '15 at 2:56
1
@iconoclast if you really want a "why they got implemented this way" read Stephane answer instead.
– Braiam
Mar 8 '15 at 16:46
2
So, @iconoclast, why is the sky blue? :) :) :)
– Jesse Chisholm
Mar 28 '16 at 18:10
|
show 3 more comments
9
In which case I guess you should use$HOME
.
– Seth
Aug 24 '14 at 20:29
11
Or you can just not quote the~
, for examplels -l ~/"My Documents"
– Andrew Medico
Aug 24 '14 at 21:47
This is very non-intuitive. What is the reason they chose to do this? (This answer doesn't actually give the reason, but rather just points to the standard, but presumably the standard was written that way for a reason.)
– iconoclast
Jan 16 '15 at 2:56
1
@iconoclast if you really want a "why they got implemented this way" read Stephane answer instead.
– Braiam
Mar 8 '15 at 16:46
2
So, @iconoclast, why is the sky blue? :) :) :)
– Jesse Chisholm
Mar 28 '16 at 18:10
9
9
In which case I guess you should use
$HOME
.– Seth
Aug 24 '14 at 20:29
In which case I guess you should use
$HOME
.– Seth
Aug 24 '14 at 20:29
11
11
Or you can just not quote the
~
, for example ls -l ~/"My Documents"
– Andrew Medico
Aug 24 '14 at 21:47
Or you can just not quote the
~
, for example ls -l ~/"My Documents"
– Andrew Medico
Aug 24 '14 at 21:47
This is very non-intuitive. What is the reason they chose to do this? (This answer doesn't actually give the reason, but rather just points to the standard, but presumably the standard was written that way for a reason.)
– iconoclast
Jan 16 '15 at 2:56
This is very non-intuitive. What is the reason they chose to do this? (This answer doesn't actually give the reason, but rather just points to the standard, but presumably the standard was written that way for a reason.)
– iconoclast
Jan 16 '15 at 2:56
1
1
@iconoclast if you really want a "why they got implemented this way" read Stephane answer instead.
– Braiam
Mar 8 '15 at 16:46
@iconoclast if you really want a "why they got implemented this way" read Stephane answer instead.
– Braiam
Mar 8 '15 at 16:46
2
2
So, @iconoclast, why is the sky blue? :) :) :)
– Jesse Chisholm
Mar 28 '16 at 18:10
So, @iconoclast, why is the sky blue? :) :) :)
– Jesse Chisholm
Mar 28 '16 at 18:10
|
show 3 more comments
Tilde expansion is defined by POSIX as:
A "tilde-prefix" consists of an unquoted <tilde> character at the beginning of a word, followed by all of the characters preceding the first unquoted <slash> in the word, or all the characters in the word if there is no <slash>. In an assignment, multiple tilde-prefixes can be used: [...] following the <equals-sign> of the assignment, following any unquoted <colon>, or both. [...] If none of the characters in the tilde-prefix are quoted, the characters in the tilde-prefix following the <tilde> are treated as a possible login name from the user database. [...] If the login name is null (that is, the tilde-prefix contains only the tilde), the tilde-prefix is replaced by the value of the variable HOME. If HOME is unset, the results are unspecified. [...]
So the shortest answer is "because it's defined that way": quoting any of the characters in the prefix, including the ~
, suppresses expansion.
It also defines the expansion as always resulting in a single word, so quoting would be unnecessary:
The pathname resulting from tilde expansion shall be treated as if quoted to prevent it being altered by field splitting and pathname expansion.
Where some of the path requires quoting, but the rest is a tilde prefix, you can combine tilde expansion and ordinary quoting straightforwardly:
$ cat ~/"file name with spaces"
On the broader "why": since there's no conceivable use for word-splitting ~
, that should be the default behaviour, rather than requiring it to be quoted. Because there's no need to quote it, giving ~
a special meaning inside quotes would be an unnecessary complication. And, of course, historical reasons mean it couldn't be changed now even if that were desirable.
According to this bash guide, tilde expansion happens before whitespace separation. Is there a way to safely do a tilde expansion, even if you home directory has whitespace in it? Ordinarily, of course, you'd do this sort of thing with""
.
– Lucretiel
Aug 21 '15 at 18:53
The expansion is a single word; see the second quoted passage in the answer.
– Michael Homer
Aug 21 '15 at 20:38
add a comment |
Tilde expansion is defined by POSIX as:
A "tilde-prefix" consists of an unquoted <tilde> character at the beginning of a word, followed by all of the characters preceding the first unquoted <slash> in the word, or all the characters in the word if there is no <slash>. In an assignment, multiple tilde-prefixes can be used: [...] following the <equals-sign> of the assignment, following any unquoted <colon>, or both. [...] If none of the characters in the tilde-prefix are quoted, the characters in the tilde-prefix following the <tilde> are treated as a possible login name from the user database. [...] If the login name is null (that is, the tilde-prefix contains only the tilde), the tilde-prefix is replaced by the value of the variable HOME. If HOME is unset, the results are unspecified. [...]
So the shortest answer is "because it's defined that way": quoting any of the characters in the prefix, including the ~
, suppresses expansion.
It also defines the expansion as always resulting in a single word, so quoting would be unnecessary:
The pathname resulting from tilde expansion shall be treated as if quoted to prevent it being altered by field splitting and pathname expansion.
Where some of the path requires quoting, but the rest is a tilde prefix, you can combine tilde expansion and ordinary quoting straightforwardly:
$ cat ~/"file name with spaces"
On the broader "why": since there's no conceivable use for word-splitting ~
, that should be the default behaviour, rather than requiring it to be quoted. Because there's no need to quote it, giving ~
a special meaning inside quotes would be an unnecessary complication. And, of course, historical reasons mean it couldn't be changed now even if that were desirable.
According to this bash guide, tilde expansion happens before whitespace separation. Is there a way to safely do a tilde expansion, even if you home directory has whitespace in it? Ordinarily, of course, you'd do this sort of thing with""
.
– Lucretiel
Aug 21 '15 at 18:53
The expansion is a single word; see the second quoted passage in the answer.
– Michael Homer
Aug 21 '15 at 20:38
add a comment |
Tilde expansion is defined by POSIX as:
A "tilde-prefix" consists of an unquoted <tilde> character at the beginning of a word, followed by all of the characters preceding the first unquoted <slash> in the word, or all the characters in the word if there is no <slash>. In an assignment, multiple tilde-prefixes can be used: [...] following the <equals-sign> of the assignment, following any unquoted <colon>, or both. [...] If none of the characters in the tilde-prefix are quoted, the characters in the tilde-prefix following the <tilde> are treated as a possible login name from the user database. [...] If the login name is null (that is, the tilde-prefix contains only the tilde), the tilde-prefix is replaced by the value of the variable HOME. If HOME is unset, the results are unspecified. [...]
So the shortest answer is "because it's defined that way": quoting any of the characters in the prefix, including the ~
, suppresses expansion.
It also defines the expansion as always resulting in a single word, so quoting would be unnecessary:
The pathname resulting from tilde expansion shall be treated as if quoted to prevent it being altered by field splitting and pathname expansion.
Where some of the path requires quoting, but the rest is a tilde prefix, you can combine tilde expansion and ordinary quoting straightforwardly:
$ cat ~/"file name with spaces"
On the broader "why": since there's no conceivable use for word-splitting ~
, that should be the default behaviour, rather than requiring it to be quoted. Because there's no need to quote it, giving ~
a special meaning inside quotes would be an unnecessary complication. And, of course, historical reasons mean it couldn't be changed now even if that were desirable.
Tilde expansion is defined by POSIX as:
A "tilde-prefix" consists of an unquoted <tilde> character at the beginning of a word, followed by all of the characters preceding the first unquoted <slash> in the word, or all the characters in the word if there is no <slash>. In an assignment, multiple tilde-prefixes can be used: [...] following the <equals-sign> of the assignment, following any unquoted <colon>, or both. [...] If none of the characters in the tilde-prefix are quoted, the characters in the tilde-prefix following the <tilde> are treated as a possible login name from the user database. [...] If the login name is null (that is, the tilde-prefix contains only the tilde), the tilde-prefix is replaced by the value of the variable HOME. If HOME is unset, the results are unspecified. [...]
So the shortest answer is "because it's defined that way": quoting any of the characters in the prefix, including the ~
, suppresses expansion.
It also defines the expansion as always resulting in a single word, so quoting would be unnecessary:
The pathname resulting from tilde expansion shall be treated as if quoted to prevent it being altered by field splitting and pathname expansion.
Where some of the path requires quoting, but the rest is a tilde prefix, you can combine tilde expansion and ordinary quoting straightforwardly:
$ cat ~/"file name with spaces"
On the broader "why": since there's no conceivable use for word-splitting ~
, that should be the default behaviour, rather than requiring it to be quoted. Because there's no need to quote it, giving ~
a special meaning inside quotes would be an unnecessary complication. And, of course, historical reasons mean it couldn't be changed now even if that were desirable.
edited Aug 24 '14 at 7:58
user44370
answered Aug 24 '14 at 1:18
Michael HomerMichael Homer
50.7k8140177
50.7k8140177
According to this bash guide, tilde expansion happens before whitespace separation. Is there a way to safely do a tilde expansion, even if you home directory has whitespace in it? Ordinarily, of course, you'd do this sort of thing with""
.
– Lucretiel
Aug 21 '15 at 18:53
The expansion is a single word; see the second quoted passage in the answer.
– Michael Homer
Aug 21 '15 at 20:38
add a comment |
According to this bash guide, tilde expansion happens before whitespace separation. Is there a way to safely do a tilde expansion, even if you home directory has whitespace in it? Ordinarily, of course, you'd do this sort of thing with""
.
– Lucretiel
Aug 21 '15 at 18:53
The expansion is a single word; see the second quoted passage in the answer.
– Michael Homer
Aug 21 '15 at 20:38
According to this bash guide, tilde expansion happens before whitespace separation. Is there a way to safely do a tilde expansion, even if you home directory has whitespace in it? Ordinarily, of course, you'd do this sort of thing with
""
.– Lucretiel
Aug 21 '15 at 18:53
According to this bash guide, tilde expansion happens before whitespace separation. Is there a way to safely do a tilde expansion, even if you home directory has whitespace in it? Ordinarily, of course, you'd do this sort of thing with
""
.– Lucretiel
Aug 21 '15 at 18:53
The expansion is a single word; see the second quoted passage in the answer.
– Michael Homer
Aug 21 '15 at 20:38
The expansion is a single word; see the second quoted passage in the answer.
– Michael Homer
Aug 21 '15 at 20:38
add a comment |
~
originates in the C-shell, long before it was added to the Korn shell and later added to the POSIX shell specification.
In the C-shell, ~
was a globbing operator (expanded by the same routine as the one expanding *.txt
for instance), so like the rest of the globbing was not performed inside double quotes.
add a comment |
~
originates in the C-shell, long before it was added to the Korn shell and later added to the POSIX shell specification.
In the C-shell, ~
was a globbing operator (expanded by the same routine as the one expanding *.txt
for instance), so like the rest of the globbing was not performed inside double quotes.
add a comment |
~
originates in the C-shell, long before it was added to the Korn shell and later added to the POSIX shell specification.
In the C-shell, ~
was a globbing operator (expanded by the same routine as the one expanding *.txt
for instance), so like the rest of the globbing was not performed inside double quotes.
~
originates in the C-shell, long before it was added to the Korn shell and later added to the POSIX shell specification.
In the C-shell, ~
was a globbing operator (expanded by the same routine as the one expanding *.txt
for instance), so like the rest of the globbing was not performed inside double quotes.
answered Aug 24 '14 at 20:41
Stéphane ChazelasStéphane Chazelas
313k57593949
313k57593949
add a comment |
add a comment |
While this doesn't answer why it's designed that way, you use $HOME
instead if you need to substitute, since that's essentially what ~
does.
$ echo "$HOME/some/path"
/home/braiam/some/path
6
this doesn't work with~otheruser
– Johannes Kuhn
Aug 24 '14 at 10:41
2
True, but you could do: THEM=~otheruser then use "$THEM/some/path"
– melds
Sep 1 '14 at 6:27
1
The workaround for~otheruser
shows what a bad idea it was to treat~
differently than variables and other things that are expanded inside double quotes.
– iconoclast
Jan 16 '15 at 2:59
add a comment |
While this doesn't answer why it's designed that way, you use $HOME
instead if you need to substitute, since that's essentially what ~
does.
$ echo "$HOME/some/path"
/home/braiam/some/path
6
this doesn't work with~otheruser
– Johannes Kuhn
Aug 24 '14 at 10:41
2
True, but you could do: THEM=~otheruser then use "$THEM/some/path"
– melds
Sep 1 '14 at 6:27
1
The workaround for~otheruser
shows what a bad idea it was to treat~
differently than variables and other things that are expanded inside double quotes.
– iconoclast
Jan 16 '15 at 2:59
add a comment |
While this doesn't answer why it's designed that way, you use $HOME
instead if you need to substitute, since that's essentially what ~
does.
$ echo "$HOME/some/path"
/home/braiam/some/path
While this doesn't answer why it's designed that way, you use $HOME
instead if you need to substitute, since that's essentially what ~
does.
$ echo "$HOME/some/path"
/home/braiam/some/path
answered Aug 24 '14 at 9:49
meldsmelds
1818
1818
6
this doesn't work with~otheruser
– Johannes Kuhn
Aug 24 '14 at 10:41
2
True, but you could do: THEM=~otheruser then use "$THEM/some/path"
– melds
Sep 1 '14 at 6:27
1
The workaround for~otheruser
shows what a bad idea it was to treat~
differently than variables and other things that are expanded inside double quotes.
– iconoclast
Jan 16 '15 at 2:59
add a comment |
6
this doesn't work with~otheruser
– Johannes Kuhn
Aug 24 '14 at 10:41
2
True, but you could do: THEM=~otheruser then use "$THEM/some/path"
– melds
Sep 1 '14 at 6:27
1
The workaround for~otheruser
shows what a bad idea it was to treat~
differently than variables and other things that are expanded inside double quotes.
– iconoclast
Jan 16 '15 at 2:59
6
6
this doesn't work with
~otheruser
– Johannes Kuhn
Aug 24 '14 at 10:41
this doesn't work with
~otheruser
– Johannes Kuhn
Aug 24 '14 at 10:41
2
2
True, but you could do: THEM=~otheruser then use "$THEM/some/path"
– melds
Sep 1 '14 at 6:27
True, but you could do: THEM=~otheruser then use "$THEM/some/path"
– melds
Sep 1 '14 at 6:27
1
1
The workaround for
~otheruser
shows what a bad idea it was to treat ~
differently than variables and other things that are expanded inside double quotes.– iconoclast
Jan 16 '15 at 2:59
The workaround for
~otheruser
shows what a bad idea it was to treat ~
differently than variables and other things that are expanded inside double quotes.– iconoclast
Jan 16 '15 at 2:59
add a comment |
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1
pubs.opengroup.org/onlinepubs/009695399/utilities/…
– llua
Aug 24 '14 at 1:12
3
Also note that this has the inconsistency when providing a program argument on command line that on command argument
--path ~/myfile
expands but--path=~/myfile
doesn't.– Ángel
Aug 24 '14 at 18:59
Related: Does ~ always equal $HOME
– Stéphane Chazelas
Aug 18 '16 at 10:41
Related (on Ask Ubuntu): Why does mkdir fail (no such file or directory) in a script with BIN_DIR=“~/bin/”?
– Eliah Kagan
Nov 17 '17 at 12:49
A variation on this theme is unix.stackexchange.com/questions/279565 .
– JdeBP
Jan 26 '18 at 16:38