| Message ID | 20231109151947.11174-3-alx@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | stpncpy.3, string_copying.7: Clarify that st[rp]ncpy() do NOT produce a string | expand |
On Thu, Nov 09, 2023 at 16:20:39 +0100, Alejandro Colomar wrote: > The previous wording could be interpreted as if the nulls were already > in place. Clarify that it's this function which pads with null bytes. > > Also, it copies "characters" from the src string. That's a bit more > specific than copying "bytes", and makes it clearer that the terminating > null byte in src is not part of the copy. > > Suggested-by: Jonny Grant <jg@jguk.org> > Cc: DJ Delorie <dj@redhat.com> > Cc: Jonny Grant <jg@jguk.org> > Cc: Matthew House <mattlloydhouse@gmail.com> > Cc: Oskari Pirhonen <xxc3ncoredxx@gmail.com> > Cc: Thorsten Kukuk <kukuk@suse.com> > Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> > Cc: Zack Weinberg <zack@owlfolio.org> > Cc: "G. Branden Robinson" <g.branden.robinson@gmail.com> > Cc: Carlos O'Donell <carlos@redhat.com> > Cc: Paul Eggert <eggert@cs.ucla.edu> > Cc: Xi Ruoyao <xry111@xry111.site> > Signed-off-by: Alejandro Colomar <alx@kernel.org> > --- > man3/stpncpy.3 | 10 ++++++---- > man3/string.3 | 11 ++--------- > man7/string_copying.7 | 3 ++- > 3 files changed, 10 insertions(+), 14 deletions(-) > ... snip ... > diff --git a/man3/string.3 b/man3/string.3 > index aba5efd2b..bd8b342a6 100644 > --- a/man3/string.3 > +++ b/man3/string.3 > @@ -179,21 +179,14 @@ .SH SYNOPSIS > .I n > bytes to > .IR dest . > -.SS Obsolete functions If you're removing this section ... > .TP > .nf > .BI "char *strncpy(char " dest "[restrict ." n "], \ > const char " src "[restrict ." n ], > .BI " size_t " n ); > .fi > -Copy at most > -.I n > -bytes from string > -.I src > -to > -.IR dest , > -returning a pointer to the start of > -.IR dest . > +Fill a fixed‐width buffer with characters from a string > +and pad with null bytes. ... shouldn't you also move the rest of this up to keep it alphabetized? - Oskari
On Thu, Nov 09, 2023 at 11:47:34PM -0600, Oskari Pirhonen wrote: > On Thu, Nov 09, 2023 at 16:20:39 +0100, Alejandro Colomar wrote: > > The previous wording could be interpreted as if the nulls were already > > in place. Clarify that it's this function which pads with null bytes. > > > > Also, it copies "characters" from the src string. That's a bit more > > specific than copying "bytes", and makes it clearer that the terminating > > null byte in src is not part of the copy. > > > > Suggested-by: Jonny Grant <jg@jguk.org> > > Cc: DJ Delorie <dj@redhat.com> > > Cc: Jonny Grant <jg@jguk.org> > > Cc: Matthew House <mattlloydhouse@gmail.com> > > Cc: Oskari Pirhonen <xxc3ncoredxx@gmail.com> > > Cc: Thorsten Kukuk <kukuk@suse.com> > > Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> > > Cc: Zack Weinberg <zack@owlfolio.org> > > Cc: "G. Branden Robinson" <g.branden.robinson@gmail.com> > > Cc: Carlos O'Donell <carlos@redhat.com> > > Cc: Paul Eggert <eggert@cs.ucla.edu> > > Cc: Xi Ruoyao <xry111@xry111.site> > > Signed-off-by: Alejandro Colomar <alx@kernel.org> > > --- > > man3/stpncpy.3 | 10 ++++++---- > > man3/string.3 | 11 ++--------- > > man7/string_copying.7 | 3 ++- > > 3 files changed, 10 insertions(+), 14 deletions(-) > > > > ... snip ... > > > diff --git a/man3/string.3 b/man3/string.3 > > index aba5efd2b..bd8b342a6 100644 > > --- a/man3/string.3 > > +++ b/man3/string.3 > > @@ -179,21 +179,14 @@ .SH SYNOPSIS > > .I n > > bytes to > > .IR dest . > > -.SS Obsolete functions > > If you're removing this section ... > > > .TP > > .nf > > .BI "char *strncpy(char " dest "[restrict ." n "], \ > > const char " src "[restrict ." n ], > > .BI " size_t " n ); > > .fi > > -Copy at most > > -.I n > > -bytes from string > > -.I src > > -to > > -.IR dest , > > -returning a pointer to the start of > > -.IR dest . > > +Fill a fixed‐width buffer with characters from a string > > +and pad with null bytes. > > ... shouldn't you also move the rest of this up to keep it alphabetized? Hi Oskari, Sure! I was trying to find a pattern in the order, but didn't see it yesterday. Thanks! :) Cheers, Alex > > - Oskari
diff --git a/man3/stpncpy.3 b/man3/stpncpy.3 index f86ff8c29..3cf4eb371 100644 --- a/man3/stpncpy.3 +++ b/man3/stpncpy.3 @@ -7,7 +7,8 @@ .SH NAME stpncpy, strncpy \- -fill a fixed-width null-padded buffer with bytes from a string +fill a fixed-width buffer with characters from a string +and pad with null bytes .SH LIBRARY Standard C library .RI ( libc ", " \-lc ) @@ -36,10 +37,11 @@ .SH SYNOPSIS _GNU_SOURCE .fi .SH DESCRIPTION -These functions copy bytes from the string pointed to by +These functions copy characters from the string pointed to by .I src -into a null-padded character sequence at the fixed-width buffer pointed to by -.IR dst . +into a character sequence at the fixed-width buffer pointed to by +.IR dst , +and pad with null bytes. If the destination buffer, limited by its size, isn't large enough to hold the copy, diff --git a/man3/string.3 b/man3/string.3 index aba5efd2b..bd8b342a6 100644 --- a/man3/string.3 +++ b/man3/string.3 @@ -179,21 +179,14 @@ .SH SYNOPSIS .I n bytes to .IR dest . -.SS Obsolete functions .TP .nf .BI "char *strncpy(char " dest "[restrict ." n "], \ const char " src "[restrict ." n ], .BI " size_t " n ); .fi -Copy at most -.I n -bytes from string -.I src -to -.IR dest , -returning a pointer to the start of -.IR dest . +Fill a fixed‐width buffer with characters from a string +and pad with null bytes. .SH DESCRIPTION The string functions perform operations on null-terminated strings. diff --git a/man7/string_copying.7 b/man7/string_copying.7 index 0e179ba34..865271c6f 100644 --- a/man7/string_copying.7 +++ b/man7/string_copying.7 @@ -41,7 +41,8 @@ .SS Strings .\" ----- SYNOPSIS :: Null-padded character sequences --------/ .SS Null-padded character sequences .nf -// Fill a fixed-width null-padded buffer with bytes from a string. +// Fill a fixed-width buffer with characters from a string +// and pad with null bytes. .BI "char *strncpy(char " dst "[restrict ." sz "], \ const char *restrict " src , .BI " size_t " sz );
The previous wording could be interpreted as if the nulls were already in place. Clarify that it's this function which pads with null bytes. Also, it copies "characters" from the src string. That's a bit more specific than copying "bytes", and makes it clearer that the terminating null byte in src is not part of the copy. Suggested-by: Jonny Grant <jg@jguk.org> Cc: DJ Delorie <dj@redhat.com> Cc: Jonny Grant <jg@jguk.org> Cc: Matthew House <mattlloydhouse@gmail.com> Cc: Oskari Pirhonen <xxc3ncoredxx@gmail.com> Cc: Thorsten Kukuk <kukuk@suse.com> Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> Cc: Zack Weinberg <zack@owlfolio.org> Cc: "G. Branden Robinson" <g.branden.robinson@gmail.com> Cc: Carlos O'Donell <carlos@redhat.com> Cc: Paul Eggert <eggert@cs.ucla.edu> Cc: Xi Ruoyao <xry111@xry111.site> Signed-off-by: Alejandro Colomar <alx@kernel.org> --- man3/stpncpy.3 | 10 ++++++---- man3/string.3 | 11 ++--------- man7/string_copying.7 | 3 ++- 3 files changed, 10 insertions(+), 14 deletions(-)