FindStr Search strings that include quotes and or backslashes must be escaped as follows.
Quotes within command line search strings must be escaped with backslash like \"
This is true for both literal and regex search strings.
Each quote may also need to be escaped for the shell (CMD.EXE or PowerShell) parser, but this has nothing to do with FINDSTR. For example, to search for a single quote you could use:
C:> FINDSTR \^" Demofile.txt
or in PowerShell:
PS C:> FINDSTR \`" Demofile.txt
Backslash in a literal search string must generally be escaped with backslash like \\
But there is a special case when the search string contains the following form:
[quote][any set of chars][1 or more backslashes][quote]
Each backslash in [1 or more backslashes] must be double escaped as \\\\
Any backslash in [any set of chars] is escaped normally as \\ as long as the last character in the set is not a backslash.
The quotes are escaped normally as \"
For example, "\a\b\\" is escaped as \"\\a\\b\\\\\\\\\"
As previously noted, one or more escaped quotes may also require escaping with ^ for the CMD parser
Backslash in a regex must be either double escaped like \\\\, or else single escaped within a character class set like [\\]
Standalone quotes and backslashes within a literal search string file specified by /G:file need not be escaped, but they can be.
" and \" are equivalent.
\ and \\ are equivalent.
If the intent is to find \\, then at least the leading backslash must be escaped. Both \\\ and \\\\ work.
If the intent is to find \", then at least the leading backslash must be escaped. Both \\" and \\\" work.
This is the one case where the escape sequences work as expected based on the documentation. Quote is not a regex metacharacter, so it need not be escaped (but can be). Backslash is a regex metacharacter, so it must be escaped.
The nul (0x00) character can appear in the file, but it functions like the C string terminator. The nul character is not searched. Any characters after a nul character are treated as a different search string as if they were on another line.
The <CR> and <LF> characters are treated as line terminators that terminate a search string, and are not included in the search.
All other single byte characters work perfectly within a file based search string.
The null character (0x00) cannot appear in a search string. Any other single byte character can appear in the string (0x01 - 0xFF). However, not all characters will match themselves. This limitation is the same for literal and regex searches.
Here is a complete list of characters that do not match themselves. Each character is represented as the decimal byte code value. The first code is the search character and the second code is the character it matches. Note - This list was compiled on a U.S. machine. I do not know what impact other languages may have on this list.
158 matches 080 199 matches 221 226 matches 071 169 matches 170 200 matches 043 227 matches 112 176 matches 221 201 matches 043 228 matches 083 177 matches 221 202 matches 045 229 matches 115 178 matches 221 203 matches 045 231 matches 116 179 matches 221 204 matches 221 232 matches 070 180 matches 221 205 matches 045 233 matches 084 181 matches 221 206 matches 043 234 matches 079 182 matches 221 207 matches 045 235 matches 100 183 matches 043 208 matches 045 236 matches 056 184 matches 043 209 matches 045 237 matches 102 185 matches 221 210 matches 045 238 matches 101 186 matches 221 211 matches 043 239 matches 110 187 matches 043 212 matches 043 240 matches 061 188 matches 043 213 matches 043 242 matches 061 189 matches 043 214 matches 043 243 matches 061 190 matches 043 215 matches 043 244 matches 040 191 matches 043 216 matches 043 245 matches 041 192 matches 043 217 matches 043 247 matches 126 193 matches 045 218 matches 043 249 matches 250 194 matches 045 219 matches 221 251 matches 118 195 matches 043 220 matches 095 252 matches 110 196 matches 045 222 matches 221 254 matches 221 197 matches 043 223 matches 095 198 matches 221 224 matches 097
Any character >0 not in the list above can be searched, including <CR> and <LF>. The easiest way to search such characters is to get them into an environment variable and use delayed expansion within the search string.
On Vista and Windows7/2008 the maximum allowed length for a single search string is 511 bytes. If any search string exceeds 511 then the result is a FINDSTR: Search string too long. error with ERRORLEVEL 2.
When doing a regular expression search, the maximum search string length is 254. A regular expression with length between 255 and 511 will result in a FINDSTR: Out of memory error with ERRORLEVEL 2. A regular expression length >511 results in the FINDSTR: Search string too long. error.
On Windows XP the maximum search string length is127 bytes for both literal and regex searches.
Files specified as a command line argument or via the /F:FILE option have no known line length limit. Searches were successfully run against a 128MB file that did not contain a single <LF>.
Piped data and Redirected input is limited to 8191 bytes per line. This limit is a "feature" of FINDSTR. It is not inherent to pipes or redirection. FINDSTR using redirected stdin or piped input will never match any line that is >=8k bytes. Lines >= 8k generate an error message to stderr, but ERRORLEVEL is still 0 if the search string is found in at least one line of at least one file.
Dave Benham - List of undocumented features and limitations of FINDSTR from StackOverflow
“Getting it round a corner is like trying to get my wardrobe up a fire escape. It's very hard work, and it's hard to see where you're going” ~Jeremy Clarkson (reviewing the BMW Z8)
FINDSTR - Search for a text string in a file.
Equivalent bash command (Linux): grep - Search file(s) for lines that match a given pattern