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Diffstat (limited to 'contrib/less/cvt.c')
-rw-r--r-- | contrib/less/cvt.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/contrib/less/cvt.c b/contrib/less/cvt.c new file mode 100644 index 0000000..ec54b59 --- /dev/null +++ b/contrib/less/cvt.c @@ -0,0 +1,120 @@ +/* + * Copyright (C) 1984-2009 Mark Nudelman + * + * You may distribute under the terms of either the GNU General Public + * License or the Less License, as specified in the README file. + * + * For more information about less, or for information on how to + * contact the author, see the README file. + */ + +/* + * Routines to convert text in various ways. Used by search. + */ + +#include "less.h" +#include "charset.h" + +extern int utf_mode; + +/* + * Get the length of a buffer needed to convert a string. + */ + public int +cvt_length(len, ops) + int len; + int ops; +{ + if (utf_mode) + /* + * Just copying a string in UTF-8 mode can cause it to grow + * in length. + * Four output bytes for one input byte is the worst case. + */ + len *= 4; + return (len + 1); +} + +/* + * Allocate a chpos array for use by cvt_text. + */ + public int * +cvt_alloc_chpos(len) + int len; +{ + int i; + int *chpos = (int *) ecalloc(sizeof(int), len); + /* Initialize all entries to an invalid position. */ + for (i = 0; i < len; i++) + chpos[i] = -1; + return (chpos); +} + +/* + * Convert text. Perform the transformations specified by ops. + * Returns converted text in odst. The original offset of each + * odst character (when it was in osrc) is returned in the chpos array. + */ + public void +cvt_text(odst, osrc, chpos, lenp, ops) + char *odst; + char *osrc; + int *chpos; + int *lenp; + int ops; +{ + char *dst; + char *src; + register char *src_end; + LWCHAR ch; + + if (lenp != NULL) + src_end = osrc + *lenp; + else + src_end = osrc + strlen(osrc); + + for (src = osrc, dst = odst; src < src_end; ) + { + int src_pos = src - osrc; + int dst_pos = dst - odst; + ch = step_char(&src, +1, src_end); + if ((ops & CVT_BS) && ch == '\b' && dst > odst) + { + /* Delete backspace and preceding char. */ + do { + dst--; + } while (dst > odst && + !IS_ASCII_OCTET(*dst) && !IS_UTF8_LEAD(*dst)); + } else if ((ops & CVT_ANSI) && IS_CSI_START(ch)) + { + /* Skip to end of ANSI escape sequence. */ + src++; /* skip the CSI start char */ + while (src < src_end) + if (!is_ansi_middle(*src++)) + break; + } else + { + /* Just copy the char to the destination buffer. */ + if ((ops & CVT_TO_LC) && IS_UPPER(ch)) + ch = TO_LOWER(ch); + put_wchar(&dst, ch); + /* + * Record the original position of the char. + * But if we've already recorded a position + * for this char (due to a backspace), leave + * it alone; if multiple source chars map to + * one destination char, we want the position + * of the first one. + */ + if (chpos != NULL && chpos[dst_pos] < 0) + chpos[dst_pos] = src_pos; + } + } + if ((ops & CVT_CRLF) && dst > odst && dst[-1] == '\r') + dst--; + *dst = '\0'; + if (lenp != NULL) + *lenp = dst - odst; + if (chpos != NULL) + chpos[dst - odst] = src - osrc; +} |