C/Strmcatf
From Attie's Wiki
(Difference between revisions)
m (Created page with 'This is a variation of <code>strcat()</code> with a few important differences / improvements: * allows you to pass a formatted string like <code>printf()</code> * automatically a…') |
m |
||
| Line 1: | Line 1: | ||
This is a variation of <code>strcat()</code> with a few important differences / improvements: | This is a variation of <code>strcat()</code> with a few important differences / improvements: | ||
* allows you to pass a formatted string like <code>printf()</code> | * allows you to pass a formatted string like <code>printf()</code> | ||
| − | * automatically allocates enough | + | * automatically allocates enough memory to extend dest (a maximum of 4096 bytes at a time) |
* returns a pointer to the <code>\0</code> at the end of dest after the operation. | * returns a pointer to the <code>\0</code> at the end of dest after the operation. | ||
Revision as of 19:12, 13 September 2011
This is a variation of strcat() with a few important differences / improvements:
- allows you to pass a formatted string like
printf() - automatically allocates enough memory to extend dest (a maximum of 4096 bytes at a time)
- returns a pointer to the
\0at the end of dest after the operation.
struct strm { char *s; int l; }; char *strmcatf(struct strm *dest, char *format, ...) { char buf[4096]; int blen; int dlen; int tlen; if (!dest) { dest = calloc(1,sizeof(struct strm)); if (!dest) return NULL; } va_list ap; va_start(ap,format); vsnprintf(buf,sizeof(buf),format,ap); va_end(ap); if (dest->s) { dlen = strlen(dest->s); } else { dlen = 0; } blen = strlen(buf); tlen = dlen + blen; if (tlen + 1 > dest->l) { dest->s = realloc(dest->s,tlen); dest->l = tlen; } strncat(dest->s,buf,blen); return &((dest->s)[tlen]); }
