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NAME | C SYNOPSIS | DESCRIPTION | COMPATIBILITY | SEE ALSO | COLOPHON |
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PMFSTRING(3) Library Functions Manual PMFSTRING(3)
pmfstring - safe string scanning
#include <pcp/pmapi.h>
ssize_t pmfstring(FILE *f, char **str);
cc ... -lpcp
pmfstring is a safe string scanning routine with semantics
similar to fscanf(3) with the %s format specifier. It scans the
input stream from f skipping initial whitespace characters, then
accumulating all the subsequent non-whitespace characters.
The main difference is that pmfstring allocates the result buffer
str using the malloc(3) family and ensures that str is (a) large
enough and (b) null-byte terminated.
Additionally pmfstring does not consider \n to be a whitespace
character in the initial scan (before filling str) and so will
not scan past the end of the current line, which is different to
fscanf(3) and better aligned with the PCP use cases.
The caller is responsible for maintaining a reference to str or
calling free(3) to release the associated storage.
On success, pmfstring returns the length of str (the same length
as strlen(3) would return) that is guaranteed to be not less than
1.
Failure is indicated by one of the following, and str is not
assigned a value:
• 0 to indicate no non-whitespace characters were found before
the end of the current line from the stream f
• -1 ( aka EOF) to indicate end of file on the stream f
• -2 to indicate some more serious failure, probably in the
malloc(3) routines; refer to errno for more information
pmfstring has similar semantics to the %ms format specifier in
some versions of fscanf(3) and the C99 fscanf_s(3) routine -
unfortunately neither of these is portable.
free(3), fscanf(3), malloc(3) and strlen(3).
This page is part of the PCP (Performance Co-Pilot) project.
Information about the project can be found at
⟨http://www.pcp.io/⟩. If you have a bug report for this manual
page, send it to pcp@groups.io. This page was obtained from the
project's upstream Git repository
⟨https://github.com/performancecopilot/pcp.git⟩ on 2023-12-22.
(At that time, the date of the most recent commit that was found
in the repository was 2023-12-16.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Performance Co-Pilot PCP PMFSTRING(3)
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HTML rendering created 2023-12-22 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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