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@xxxxxx>
---
strbuf.c | 11 ++++++++---
strbuf.h | 12 ++++++++++++
2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/strbuf.c b/strbuf.c
index 08eec8f1d8..31dc48c0ab 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -721,11 +721,11 @@ static int strbuf_getdelim(struct strbuf *sb, FILE *fp, int term)
return 0;
}
-int strbuf_getline(struct strbuf *sb, FILE *fp)
+int strbuf_getdelim_strip_crlf(struct strbuf *sb, FILE *fp, int term)
{
- if (strbuf_getwholeline(sb, fp, '\n'))
+ if (strbuf_getwholeline(sb, fp, term))
return EOF;
- if (sb->buf[sb->len - 1] == '\n') {
+ if (term == '\n' && sb->buf[sb->len - 1] == '\n') {
strbuf_setlen(sb, sb->len - 1);
if (sb->len && sb->buf[sb->len - 1] == '\r')
strbuf_setlen(sb, sb->len - 1);
@@ -733,6 +733,11 @@ int strbuf_getline(struct strbuf *sb, FILE *fp)
return 0;
}
+int strbuf_getline(struct strbuf *sb, FILE *fp)
+{
+ return strbuf_getdelim_strip_crlf(sb, fp, '\n');
+}
+
int strbuf_getline_lf(struct strbuf *sb, FILE *fp)
{
return strbuf_getdelim(sb, fp, '\n');
diff --git a/strbuf.h b/strbuf.h
index 3dfeadb44c..0e69b656bc 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -475,6 +475,18 @@ int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint);
*/
ssize_t strbuf_write(struct strbuf *sb, FILE *stream);
+/**
+ * Read from a FILE * until the specified terminator is encountered,
+ * overwriting the existing contents of the strbuf.
+ *
+ * Reading stops after the terminator or at EOF. The terminator is
+ * removed from the buffer before returning. If the terminator is LF
+ * and if it is preceded by a CR, then the whole CRLF is stripped.
+ * Returns 0 unless there was nothing left before EOF, in which case
+ * it returns `EOF`.
+ */
+int strbuf_getdelim_strip_crlf(struct strbuf *sb, FILE *fp, int term);
+
/**
* Read a line from a FILE *, overwriting the existing contents of
* the strbuf. The strbuf_getline*() family of functions share
--
2.40.1
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