C/Strncatf
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(Difference between revisions)
| Line 1: | Line 1: | ||
| − | This is a variation of <code>strcat()</code> | + | 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> | ||
| + | * takes a max length for dest, not for how much of src to use (like <code>strncat()</code>) | ||
| + | * returns a pointer to the <code>\0</code> at the end of dest after the operation. | ||
| + | |||
<source lang="c"> | <source lang="c"> | ||
char *strncatf(char *dest, int length, char *format, ...) { | char *strncatf(char *dest, int length, char *format, ...) { | ||
| Line 9: | Line 13: | ||
length -= strlen(dest); | length -= strlen(dest); | ||
strncat(dest,buf,length-1); | strncat(dest,buf,length-1); | ||
| + | return &dest[strlen(dest)]; | ||
} | } | ||
</source> | </source> | ||
Revision as of 14:28, 4 March 2010
This is a variation of strcat() with a few important differences / improvements:
- allows you to pass a formatted string like
printf() - takes a max length for dest, not for how much of src to use (like
strncat()) - returns a pointer to the
\0at the end of dest after the operation.
char *strncatf(char *dest, int length, char *format, ...) { char buf[4096]; va_list ap; va_start(ap,format); vsnprintf(buf,sizeof(buf),format,ap); va_end(ap); length -= strlen(dest); strncat(dest,buf,length-1); return &dest[strlen(dest)]; }
