Thread (24 messages) 24 messages, 2 authors, 2025-03-23

[PATCH v2 0/2] strto[u]l(3) BUGS and CAVEATS

From: Alejandro Colomar <alx@kernel.org>
Date: 2025-03-21 22:18:16

Hi Bruno,

This time, I've added a mention to white space.  I've decided to put
both bugs in the same commit.

And I've added a commit clarifying how to do range checks correctly.


Have a lovely night!
Alex

Alejandro Colomar (2):
  man/man3/strto[u]l.3: BUGS: Signed numbers and white space are not
    rejected
  man/man3/strtol.3: CAVEATS: Clarify how to perform range checks

 man/man3/strtol.3  | 20 ++++++++++++++++++++
 man/man3/strtoul.3 | 19 ++++++++++++++-----
 2 files changed, 34 insertions(+), 5 deletions(-)

Range-diff against v1:
1:  939641570 ! 1:  8faa6a809 man/man3/strtoul.3: BUGS: Signed numbers are not rejected
    @@ Metadata
     Author: Alejandro Colomar [off-list ref]
     
      ## Commit message ##
    -    man/man3/strtoul.3: BUGS: Signed numbers are not rejected
    +    man/man3/strto[u]l.3: BUGS: Signed numbers and white space are not rejected
     
         Reported-by: Bruno Haible [off-list ref]
         Signed-off-by: Alejandro Colomar [off-list ref]
     
    + ## man/man3/strtol.3 ##
    +@@ man/man3/strtol.3: .SH CAVEATS
    +     goto unsupported_base;
    + .EE
    + .in
    ++.SH BUGS
    ++.SS White space
    ++These functions silently accept leading white space.
    ++One should call
    ++.BR isspace (3)
    ++before
    ++.BR strtol ()
    ++to reject white space.
    + .SH EXAMPLES
    + The program shown below demonstrates the use of
    + .BR strtol ().
    +
      ## man/man3/strtoul.3 ##
     @@ man/man3/strtoul.3: .SH CAVEATS
      and then determine if an error occurred by checking whether
    @@ man/man3/strtoul.3: .SH CAVEATS
     -Negative values are considered valid input and are
     -silently converted to the equivalent
     -.I "unsigned long"
    +-value.
     +.SH BUGS
     +.SS Signed numbers
     +Negative values
     +are considered valid input and
    -+are silently converted to the equivalent
    -+.I unsigned long
    - value.
    -+.P
    -+Users should reject signed numbers
    -+with a wrapper function.
    -+.IP
    -+.EX
    -+unsigned long
    -+strtoul_u(const char *restrict s, char **restrict endp, int base)
    -+{
    -+	while (isspace((unsigned char) *s))
    -+		s++;
    -+	if (!isxdigit((unsigned char) *s))
    -+		return 0;
    -+\&
    -+	return strtoul(s, endp, base);
    -+}
    -+.EE
    ++are silently converted to
    ++.IR "\%unsigned\ long" .
    ++.SS White space
    ++These functions silently accept leading whitespace.
    ++.SS isxdigit(3)
    ++One should call
    ++.BR isxdigit (3)
    ++before
    ++.BR strtoul ()
    ++to reject white space and/or a sign.
      .SH EXAMPLES
      See the example on the
      .BR strtol (3)
-:  --------- > 2:  b5244e62c man/man3/strtol.3: CAVEATS: Clarify how to perform range checks

base-commit: e921861a3d30cfc5f9263747a4e64a68e488288c
-- 
2.47.2

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