oracular (3) pmfstring.3.gz

NAME

       pmfstring - safe string scanning

C SYNOPSIS

       #include <pcp/pmapi.h>

       ssize_t pmfstring(FILE *f, char **str);

       cc ... -lpcp

DESCRIPTION

       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

COMPATIBILITY

       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.

SEE ALSO

       free(3), fscanf(3), malloc(3) and strlen(3).