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Re: strsup - supplementary string functions

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Malcolm McLean <malcolm.mclean5@btinternet.com> wrote:
> I'm putting together a little library of supplementary string functions,
> strsup.c.
> 
> The functions are intended to be fairly short, and to operate on char *s.
> They should ideally be implementable as a single function which can be
> snipped and pasted.
> 
> Unlike the string.h functions they can depend on malloc().
> 
> The obvious first function is strdup().
> 
> I've also got
> 
> strcount - count the instances of character ch in str.
> trim - remove leadign and trailing whitespace from a string
> singlespace - repalce all runs of whitespace in a string with a single 
> space character.
> split - return an array of fields, split on a delimiter character.
> compnumeric - compare two strings with embedded numbers.
> replace - replace all substrings with new passed string.
> 
> Any ideas for more?

Some might be implemented as macros, especially the snipped-and-pasted
variety. Several snipped-and-pasted examples from my programs are below.
Some do little more than arg-checking, e.g., to avoid segfaulting if
used with a NULL ptr.
  Want about ten zillion other ideas (some arguably a bit over-the-top)?
Look at the VMS documentation about lexical string functions in DCL
(DEC's shell DCL="digital command language"),
  openvms.compaq.com/doc/73final/6489/6489pro_047.html#66_manipulatingstrings

/* ---
 * macro to skip whitespace
 * ------------------------ */
#define WHITESPACE  " \t\n\r\f\v"       /* skipped whitespace chars */
#define skipwhite(thisstr)  if ( (thisstr) != NULL ) \
        thisstr += strspn(thisstr,WHITESPACE)
/* ---
 * macros to check if a string is empty
 * ------------------------------------ */
#define isempty(s)  ((s)==NULL?1:(*(s)=='\000'?1:0))
/* ---
 * macro to strip leading and trailing whitespace
 * ---------------------------------------------- */
#define trimwhite(thisstr) if ( (thisstr) != NULL ) { \
        int thislen = strlen(thisstr); \
        while ( --thislen >= 0 ) \
          if ( isthischar((thisstr)[thislen],WHITESPACE) ) \
            (thisstr)[thislen] = '\000'; \
          else break; \
        if ( (thislen = strspn((thisstr),WHITESPACE)) > 0 ) \
          {strsqueeze((thisstr),thislen);} } else /*user adds ;*/
/* ---
 * macro to remove all 'c' chars from s
 * ------------------------------------ */
#define compress(s,c) if(!isempty(s))   /* remove embedded c's from s */ \
        { char *p; while((p=strchr((s),(c)))!=NULL) {strsqueeze(p,1);} } else
/* ---
 * macro to strcpy(s,s+n) using memmove() (also works for negative n)
 * ------------------------------------------------------------------ */
#define strsqueeze(s,n) if((n)!=0) { if(!isempty((s))) { \
        int thislen3=strlen(s); \
        if ((n) >= thislen3) *(s) = '\000'; \
        else memmove((s),((s)+(n)),(1+thislen3-(n))); }} else /*user adds ;*/
/* ---
 * macro to strncpy() n bytes and make sure it's null-terminated
 * ------------------------------------------------------------- */
#define strninit(target,source,n) \
        if( (target)!=NULL && (n)>=0 ) { \
          char *thissource = (source); \
          (target)[0] = '\000'; \
          if ( (n)>0 && thissource!=NULL ) { \
            strncpy((target),thissource,(n)); \
            (target)[(n)] = '\000'; } }
/* ---
 * macro to check for thischar inthisstr
 * ------------------------------------- */
#define isthischar(thischar,inthisstr) \
        ( (thischar)!='\000' && *(inthisstr)!='\000' \
        && strchr(inthisstr,(thischar))!=(char *)NULL )
/* ---
 * macro for last char of a string
 * ------------------------------- */
#define lastchar(s) (isempty(s)?'\000':*((s)+(strlen(s)-1)))

-- 
John Forkosh  ( mailto:  j@f.com  where j=john and f=forkosh )

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strsup - supplementary string functions Malcolm McLean <malcolm.mclean5@btinternet.com> - 2013-01-22 10:14 -0800
  Re: strsup - supplementary string functions Keith Thompson <kst-u@mib.org> - 2013-01-22 11:23 -0800
    Re: strsup - supplementary string functions James Kuyper <jameskuyper@verizon.net> - 2013-01-22 14:34 -0500
      Re: strsup - supplementary string functions Keith Thompson <kst-u@mib.org> - 2013-01-22 11:44 -0800
  Re: strsup - supplementary string functions Johann Klammer <klammerj@NOSPAM.a1.net> - 2013-01-22 22:57 +0100
  Re: strsup - supplementary string functions Jorgen Grahn <grahn+nntp@snipabacken.se> - 2013-01-23 21:13 +0000
    Re: strsup - supplementary string functions Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-01-23 23:08 +0000
  Re: strsup - supplementary string functions Bjorn Augestad <bjorn.augestad@gmail.com> - 2013-01-23 22:54 +0100
  Re: strsup - supplementary string functions Dr Nick <nospam-4@temporary-address.org.uk> - 2013-01-24 07:44 +0000
    Re: strsup - supplementary string functions Malcolm McLean <malcolm.mclean5@btinternet.com> - 2013-01-24 01:12 -0800
      Re: strsup - supplementary string functions "BartC" <bc@freeuk.com> - 2013-01-25 18:27 +0000
        Re: strsup - supplementary string functions Malcolm McLean <malcolm.mclean5@btinternet.com> - 2013-01-28 01:24 -0800
  Re: strsup - supplementary string functions John McCue <jmccue@jmcbsd0.hsd1.ma.comcast.net> - 2013-01-24 22:28 +0000
  Re: strsup - supplementary string functions JohnF <john@please.see.sig.for.email.com> - 2013-01-25 10:57 +0000
    Re: strsup - supplementary string functions 88888 Dihedral <dihedral88888@googlemail.com> - 2013-01-25 12:45 -0800
  Re: strsup - supplementary string functions ssmitch@gmail.com - 2013-01-29 08:17 -0800
    Re: strsup - supplementary string functions Malcolm McLean <malcolm.mclean5@btinternet.com> - 2013-01-29 09:57 -0800
    Re: strsup - supplementary string functions Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-01-30 03:46 +0000
      Re: strsup - supplementary string functions Tim Rentsch <txr@alumni.caltech.edu> - 2013-01-31 14:50 -0800
        Re: strsup - supplementary string functions Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-02-02 02:45 +0000
          Re: strsup - supplementary string functions Tim Rentsch <txr@alumni.caltech.edu> - 2013-02-03 14:33 -0800

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