diff options
Diffstat (limited to 'builtin-stripspace.c')
-rw-r--r-- | builtin-stripspace.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/builtin-stripspace.c b/builtin-stripspace.c new file mode 100644 index 0000000000..916355ca5d --- /dev/null +++ b/builtin-stripspace.c @@ -0,0 +1,99 @@ +#include "builtin.h" +#include "cache.h" + +/* + * Returns the length of a line, without trailing spaces. + * + * If the line ends with newline, it will be removed too. + */ +static size_t cleanup(char *line, size_t len) +{ + if (len) { + if (line[len - 1] == '\n') + len--; + + while (len) { + unsigned char c = line[len - 1]; + if (!isspace(c)) + break; + len--; + } + } + return len; +} + +/* + * Remove empty lines from the beginning and end + * and also trailing spaces from every line. + * + * Note that the buffer will not be NUL-terminated. + * + * Turn multiple consecutive empty lines between paragraphs + * into just one empty line. + * + * If the input has only empty lines and spaces, + * no output will be produced. + * + * If last line has a newline at the end, it will be removed. + * + * Enable skip_comments to skip every line starting with "#". + */ +size_t stripspace(char *buffer, size_t length, int skip_comments) +{ + int empties = -1; + size_t i, j, len, newlen; + char *eol; + + for (i = j = 0; i < length; i += len, j += newlen) { + eol = memchr(buffer + i, '\n', length - i); + len = eol ? eol - (buffer + i) + 1 : length - i; + + if (skip_comments && len && buffer[i] == '#') { + newlen = 0; + continue; + } + newlen = cleanup(buffer + i, len); + + /* Not just an empty line? */ + if (newlen) { + if (empties != -1) + buffer[j++] = '\n'; + if (empties > 0) + buffer[j++] = '\n'; + empties = 0; + memmove(buffer + j, buffer + i, newlen); + continue; + } + if (empties < 0) + continue; + empties++; + } + + return j; +} + +int cmd_stripspace(int argc, const char **argv, const char *prefix) +{ + char *buffer; + unsigned long size; + int strip_comments = 0; + + if (argc > 1 && (!strcmp(argv[1], "-s") || + !strcmp(argv[1], "--strip-comments"))) + strip_comments = 1; + + size = 1024; + buffer = xmalloc(size); + if (read_fd(0, &buffer, &size)) { + free(buffer); + die("could not read the input"); + } + + size = stripspace(buffer, size, strip_comments); + write_or_die(1, buffer, size); + if (size) + putc('\n', stdout); + + free(buffer); + return 0; +} |