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index a9668e5f2d2b1a7ffac45e4111ca6d8a4818af2b..afe27599511c5f6bab6e4f799fd18e7d83bdd454 100644 (file)
strbufs has some invariants that are very important to keep in mind:
-. The `buf` member is never NULL, so you it can be used in any usual C
+. The `buf` member is never NULL, so it can be used in any usual C
string operations safely. strbuf's _have_ to be initialized either by
`strbuf_init()` or by `= STRBUF_INIT` before the invariants, though.
+
buffer from its strbuf shell in a safe way. That is the sole supported
way. This will give you a malloced buffer that you can later `free()`.
+
-However, it it totally safe to modify anything in the string pointed by
+However, it is totally safe to modify anything in the string pointed by
the `buf` member, between the indices `0` and `len-1` (inclusive).
. The `buf` member is a byte array that has at least `len + 1` bytes
* `struct strbuf`
-This is string buffer structure. The `len` member can be used to
+This is the string buffer structure. The `len` member can be used to
determine the current length of the string, and `buf` member provides access to
the string itself.
* Adding data to the buffer
-NOTE: All of these functions in this section will grow the buffer as
- necessary.
+NOTE: All of the functions in this section will grow the buffer as necessary.
+If they fail for some reason other than memory shortage and the buffer hadn't
+been allocated before (i.e. the `struct strbuf` was set to `STRBUF_INIT`),
+then they will free() it.
`strbuf_addch`::
the length of the placeholder recognized and `strbuf_expand()` skips
over it.
+
+The format `%%` is automatically expanded to a single `%` as a quoting
+mechanism; callers do not need to handle the `%` placeholder themselves,
+and the callback function will not be invoked for this placeholder.
++
All other characters (non-percent and not skipped ones) are copied
verbatim to the strbuf. If the callback returned zero, meaning that the
placeholder is unknown, then the percent sign is copied, too.
parameters to the callback, `strbuf_expand()` passes a context pointer,
which can be used by the programmer of the callback as she sees fit.
+`strbuf_expand_dict_cb`::
+
+ Used as callback for `strbuf_expand()`, expects an array of
+ struct strbuf_expand_dict_entry as context, i.e. pairs of
+ placeholder and replacement string. The array needs to be
+ terminated by an entry with placeholder set to NULL.
+
+`strbuf_addbuf_percentquote`::
+
+ Append the contents of one strbuf to another, quoting any
+ percent signs ("%") into double-percents ("%%") in the
+ destination. This is useful for literal data to be fed to either
+ strbuf_expand or to the *printf family of functions.
+
`strbuf_addf`::
Add a formatted string to the buffer.
Read a given size of data from a FILE* pointer to the buffer.
+
-NOTE: The buffer is rewinded if the read fails. If -1 is returned,
+NOTE: The buffer is rewound if the read fails. If -1 is returned,
`errno` must be consulted, like you would do for `read(3)`.
`strbuf_read()`, `strbuf_read_file()` and `strbuf_getline()` has the
same behaviour as well.
Read the contents of a file, specified by its path. The third argument
can be used to give a hint about the file size, to avoid reallocs.
+`strbuf_readlink`::
+
+ Read the target of a symbolic link, specified by its path. The third
+ argument can be used to give a hint about the size, to avoid reallocs.
+
`strbuf_getline`::
Read a line from a FILE* pointer. The second argument specifies the line
comments are considered contents to be removed or not.
`launch_editor`::
+
+ Launch the user preferred editor to edit a file and fill the buffer
+ with the file's contents upon the user completing their editing. The
+ third argument can be used to set the environment which the editor is
+ run in. If the buffer is NULL the editor is launched as usual but the
+ file's contents are not read into the buffer upon completion.