diff options
Diffstat (limited to 'urt/rle_putcom.c')
| -rw-r--r-- | urt/rle_putcom.c | 156 |
1 files changed, 60 insertions, 96 deletions
diff --git a/urt/rle_putcom.c b/urt/rle_putcom.c index ab2eb208..ff27cb20 100644 --- a/urt/rle_putcom.c +++ b/urt/rle_putcom.c @@ -1,23 +1,23 @@ /* * This software is copyrighted as noted below. It may be freely copied, - * modified, and redistributed, provided that the copyright notice is + * modified, and redistributed, provided that the copyright notice is * preserved on all copies. - * + * * There is no warranty or other guarantee of fitness for this software, * it is provided solely "as is". Bug reports or fixes may be sent * to the author, who may or may not act on them as he desires. * * You may not include this software in a program or other software product - * without supplying the source, or without informing the end-user that the + * without supplying the source, or without informing the end-user that the * source is available for no extra charge. * * If you modify this software, you should include a notice giving the * name of the person performing the modification, the date of modification, * and the reason for such modification. */ -/* +/* * rle_putcom.c - Add a picture comment to the header struct. - * + * * Author: Spencer W. Thomas * Computer Science Dept. * University of Utah @@ -25,34 +25,35 @@ * Copyright (c) 1987, University of Utah */ +#include <limits.h> +#include <assert.h> #include <stdio.h> #include "netpbm/mallocvar.h" #include "netpbm/pm.h" #include "rle.h" -/***************************************************************** - * TAG( match ) - * - * Match a name against a test string for "name=value" or "name". - * If it matches name=value, return pointer to value part, if just - * name, return pointer to NUL at end of string. If no match, return NULL. - * - * Inputs: - * n: Name to match. May also be "name=value" to make it easier - * to replace comments. - * v: Test string. - * Outputs: - * Returns pointer as above. - * Assumptions: - * [None] - * Algorithm: - * [None] - */ + + static const char * match(const char * const nArg, const char * const vArg) { - +/*---------------------------------------------------------------------------- + Match a name against a test string for "name=value" or "name". + If it matches name=value, return pointer to value part, if just + name, return pointer to NUL at end of string. If no match, return NULL. + + Inputs: + n: Name to match. May also be "name=value" to make it easier + to replace comments. + v: Test string. + Outputs: + Returns pointer as above. + Assumptions: + [None] + Algorithm: + [None] +-----------------------------------------------------------------------------*/ const char * n; const char * v; @@ -70,56 +71,59 @@ match(const char * const nArg, -/***************************************************************** - * TAG( rle_putcom ) - * - * Put a comment into the header struct. - * Inputs: - * value: Value to add to comments. - * the_hdr: Header struct to add to. - * Outputs: - * the_hdr: Modified header struct. - * Returns previous value; - * Assumptions: - * value pointer can be used as is (data is NOT copied). - * Algorithm: - * Find match if any, else add at end (realloc to make bigger). - */ const char * rle_putcom(const char * const value, - rle_hdr * const the_hdr) { - - if ( the_hdr->comments == NULL) { - MALLOCARRAY_NOFAIL(the_hdr->comments, 2); - the_hdr->comments[0] = value; - the_hdr->comments[1] = NULL; + rle_hdr * const hdrP) { +/*---------------------------------------------------------------------------- + Put a comment into the header struct, replacing the existing one + that has the same key, if there is one. + Inputs: + value: Value to add to comments. + *hdrP: Header struct to add to. + Outputs: + *hdrP: Modified header struct. + Returns previous comment having the same key; NULL if none + Assumptions: + value pointer can be used as is (data is NOT copied). + Algorithm: + Find match if any, else add at end (realloc to make bigger). +-----------------------------------------------------------------------------*/ + if ( hdrP->comments == NULL) { + MALLOCARRAY_NOFAIL(hdrP->comments, 2); + hdrP->comments[0] = value; + hdrP->comments[1] = NULL; } else { const char ** cp; const char * v; - const char ** old_comments; - int i; - for (i = 2, cp = the_hdr->comments; *cp != NULL; ++i, ++cp) + const char ** oldComments; + unsigned int i; + + for (i = 2, cp = hdrP->comments; + *cp != NULL && i < UINT_MAX; + ++i, ++cp) { if (match(value, *cp) != NULL) { v = *cp; *cp = value; return v; } + } /* Not found */ /* Can't realloc because somebody else might be pointing to this * comments block. Of course, if this were true, then the * assignment above would change the comments for two headers. - * But at least, that won't crash the program. Realloc will. + * But at least that won't crash the program. Realloc will. * This would work a lot better in C++, where hdr1 = hdr2 * could copy the pointers, too. */ - old_comments = the_hdr->comments; - MALLOCARRAY(the_hdr->comments, i); - if (the_hdr->comments == NULL) + oldComments = hdrP->comments; + MALLOCARRAY(hdrP->comments, i); + if (hdrP->comments == NULL) pm_error("Unable to allocate memory for comments"); - the_hdr->comments[--i] = NULL; - the_hdr->comments[--i] = value; - for (--i; i >= 0; --i) - the_hdr->comments[i] = old_comments[i]; + assert(i >= 2); + hdrP->comments[--i] = NULL; + hdrP->comments[--i] = value; + for (; i > 0; --i) + hdrP->comments[i-1] = oldComments[i-1]; } return NULL; @@ -127,43 +131,3 @@ rle_putcom(const char * const value, -/***************************************************************** - * TAG( rle_delcom ) - * - * Delete a comment from header struct. - * Inputs: - * name: Name of comment to delete. - * the_hdr: Header to delete comment from. - * Outputs: - * the_hdr: Modified header struct. - * Returns original comment value. - * Assumptions: - * [None] - * Algorithm: - * [None] - */ -const char * -rle_delcom(const char * const name, - rle_hdr * const the_hdr) { - - const char * v = NULL; - - if (the_hdr->comments == NULL) - v = NULL; - else { - const char ** cp; - - for (cp = the_hdr->comments; *cp != NULL; ++cp) - if (match(name, *cp) != NULL) { - v = *cp; - for ( ; *cp != NULL; ++cp) - *cp = cp[1]; - break; - } - /* Not found */ - if (*the_hdr->comments == NULL) - the_hdr->comments = NULL; - } - - return v; -} |