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Diffstat (limited to 'src/string/stpnmove.c')
| -rw-r--r-- | src/string/stpnmove.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/src/string/stpnmove.c b/src/string/stpnmove.c new file mode 100644 index 0000000..a0a0de9 --- /dev/null +++ b/src/string/stpnmove.c @@ -0,0 +1,47 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#include <string.h> + + + +/** + * Copy a memory segment to another, possibly overlapping, segment, + * stop when a NUL byte is encountered. + * + * This is a slibc extension added for completeness. + * It is only available if GNU extensions are available. + * + * @param whither The destination memory segment. + * @param whence The source memory segment. + * @param maxlen The maximum number of bytes to copy. + * NOTE that if the resulting string at least this + * long, no NUL byte will be written to `whither'. + * On the otherhand, if the resultnig string is + * shorter, `whither` will be filled with NUL bytes + * until this amount of bytes have been written. + * @return `whither` plus the number of written bytes, + * excluding NUL bytes, is returned. + */ +char* stpnmove(char* whither, const char* whence, size_t maxlen) +{ + size_t n = strnlen(whence, maxlen); + memmove(whither, whence, n); + memset(whither, 0, maxlen - n); + return whither + n; +} + |