strcstr(3pub) [debian man page]

STRCSTR(3pub)						       C Programmer's Manual						     STRCSTR(3pub)

NAME

       strcstr - convert memory block to printable C string notation

SYNOPSIS

       #include <publib.h>
       void strcstr(char *str, size_t max, const void *block, size_t n);

DESCRIPTION

       strcstr	converts  the  contents  of an arbitrary memory block (which need not be a zero terminated string) into a printable notation using
       normal C string literal syntax.	This can be used for example to store potentially binary data in a file, or in debugging outputs.

       All characters for which there is a simple shorthand escape sequence (', ", ?, , a, , f, 
, 
, 	, v) are stored using  that  nota-
       tion.   is stored as .  All other non-printable characters are stored using a hexadecimal escape sequence.  All other printable charac-
       ters are stored as is.

       The isprint(3) macro is used to determine whether a character is printable (i.e., whether it is printed as is, or using special	notation).
       Therefore, the output depends on the locale.

RETURN VALUE

       strcstr returns nothing.

EXAMPLE

       The  following  code dumps input to the standard output in a guaranteed (modulo locale bugs) printable format.  It might be used for debug-
       ging.

	    #include <stdio.h>
	    #include <publib.h>

	    int main(void) {
		 char line[512];
		 char cstr[512*(CHAR_BIT/4+1+2)+1];  /* +2 for x, +1 for ,
					  the rest to be able to
					  store the hex code for
					  512 chars.  */

		 while (fgets(line, sizeof(line), stdin) != NULL) {
		      strcstr(cstr, sizeof(cstr), line, strlen(line));
		      printf("%s0, cstr);
		 }
		 return 0;
	    }

SEE ALSO

       publib(3), strins(3)

AUTHOR

       Lars Wirzenius (lars.wirzenius@helsinki.fi)

Publib							       C Programmer's Manual						     STRCSTR(3pub)

XMALLOC(3pub)						       C Programmer's Manual						     XMALLOC(3pub)

NAME

       xmalloc, xrealloc, xfree, xstrdup, xmemdup, memdup - memory allocation functions for Publib

SYNOPSIS

       #include <publib.h>

       void *xmalloc(size_t bytes);
       void *xrealloc(void *ptr, size_t bytes);
       void xfree(void *ptr);
       char *xstrdup(const char *string);
       void *memdup(const void *mem, size_t bytes);
       void *xmemdup(const void *mem, size_t bytes);

DESCRIPTION

       These  functions are utility functions for memory allocation from the publib library.  xmalloc, xrealloc, and xfree are error checking ver-
       sions of the standard library routines malloc, realloc, and free, respectively.	They are guaranteed to never return unless  there  was	no
       problem:  if, for example, xmalloc is unable to allocate the requested amount of memory, it prints an error message and terminates the pro-
       gram.  Hence, the caller does not need to check for a NULL return value, and the code that calls these functions is simpler due to the lack
       of error checks.

       Similarly,  xstrdup  is an error checking version of the common (though not standard) strdup routine, which creates a duplicate of a string
       by allocating memory for the copy with malloc.  (For systems that lack strdup, publib provides one in its portability module; it is  always
       declared in <publib.h>.)

       memdup  is  similar to strdup, it creates a copy of an arbitrary memory area (the arguments are a pointer to the beginning of the area, and
       its size) by allocating memory for the copy with malloc.  xmemdup is its error checking version.

NOTE

       xmalloc and xrealloc treat a request to allocate a block of 0 bytes as an error.  xrealloc will allow its first argument to be NULL.

SEE ALSO

       publib(3), malloc(3), strdup(3)

AUTHOR

       Lars Wirzenius (lars.wirzenius@helsinki.fi)

Publib							       C Programmer's Manual						     XMALLOC(3pub)