@matheusbsbs / matheus-bagliano / commits / af35e56b0f

strbuf: provide CRLF-aware helper to read until a specified delimiter

Many of our commands support reading input that is separated either via newlines or via NUL characters. Furthermore, in order to be a better cross platform citizen, these commands typically know to strip the CRLF sequence so that we also support reading newline-separated inputs on e.g. the Windows platform. This results in the following kind of awkward pattern: ``` struct strbuf input = STRBUF_INIT; while (1) { int ret; if (nul_terminated) ret = strbuf_getline_nul(&input, stdin); else ret = strbuf_getline(&input, stdin); if (ret) break; ... } ``` Introduce a new CRLF-aware helper function that can read up to a user specified delimiter. If the delimiter is `\n` the function knows to also strip CRLF, otherwise it will only strip the specified delimiter. This results in the following, much more readable code pattern: ``` struct strbuf input = STRBUF_INIT; while (strbuf_getdelim_strip_crlf(&input, stdin, delim) != EOF) { ... } ``` The new function will be used in a subsequent commit. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Patrick Steinhardt committed Jun 6, 2023 at 07:19 UTC af35e56b0f83f872a8d82d8293fae87c80b491ef

2 files changed +20 -3

strbuf.c

+8 -3

@@ -721,11 +721,11 @@ static int strbuf_getdelim(struct strbuf *sb, FILE *fp, int term)

721 return 0;

722 }

723

724 -int strbuf_getline(struct strbuf *sb, FILE *fp)

724 +int strbuf_getdelim_strip_crlf(struct strbuf *sb, FILE *fp, int term)

725 {

726 - if (strbuf_getwholeline(sb, fp, '\n'))

726 + if (strbuf_getwholeline(sb, fp, term))

727 return EOF;

728 - if (sb->buf[sb->len - 1] == '\n') {

728 + if (term == '\n' && sb->buf[sb->len - 1] == '\n') {

729 strbuf_setlen(sb, sb->len - 1);

730 if (sb->len && sb->buf[sb->len - 1] == '\r')

731 strbuf_setlen(sb, sb->len - 1);

@@ -733,6 +733,11 @@ int strbuf_getline(struct strbuf *sb, FILE *fp)

733 return 0;

734 }

735

736 +int strbuf_getline(struct strbuf *sb, FILE *fp)

737 +{

738 + return strbuf_getdelim_strip_crlf(sb, fp, '\n');

739 +}

740 +

741 int strbuf_getline_lf(struct strbuf *sb, FILE *fp)

742 {

743 return strbuf_getdelim(sb, fp, '\n');

strbuf.h

+12

@@ -475,6 +475,18 @@ int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint);

475 */

476 ssize_t strbuf_write(struct strbuf *sb, FILE *stream);

477

478 +/**

479 + * Read from a FILE * until the specified terminator is encountered,

480 + * overwriting the existing contents of the strbuf.

481 + *

482 + * Reading stops after the terminator or at EOF. The terminator is

483 + * removed from the buffer before returning. If the terminator is LF

484 + * and if it is preceded by a CR, then the whole CRLF is stripped.

485 + * Returns 0 unless there was nothing left before EOF, in which case

486 + * it returns `EOF`.

487 + */

488 +int strbuf_getdelim_strip_crlf(struct strbuf *sb, FILE *fp, int term);

489 +

490 /**

491 * Read a line from a FILE *, overwriting the existing contents of

492 * the strbuf. The strbuf_getline*() family of functions share