I have a database controlfile on a Linux system that I want to filter out (for training purposes). However, I am unable to find a proper way to get rid of "block-like" characters:
▒▒▒▒ ▒▒▒▒ ▒▒▒▒ ▒▒▒▒▒ ▒▒▒{ ▒▒▒▒▒▒9 ▒▒▒▒ ▒▒▒▒▒ I've tried many ways, but they do not get rid of the block chars:
258 strings o1_mf_d3rrgv0l_.ctl|grep -vE '▒' 259 strings o1_mf_d3rrgv0l_.ctl|grep -vE '@|?|+|(|)|<|>' 260 strings o1_mf_d3rrgv0l_.ctl|grep -vE '@|\?|\+|(|)|<|>' 261 strings o1_mf_d3rrgv0l_.ctl|grep -vE '@|\?|\+|\(|\)|\<|\>' 262 strings o1_mf_d3rrgv0l_.ctl|grep -vE '@|\?|\+|\(|\)|\<|\>|!' 263 strings o1_mf_d3rrgv0l_.ctl|grep -vE '@|\?|\+|\(|\)|\<|\>|!|\^|\%|\`' 264 strings o1_mf_d3rrgv0l_.ctl|grep -vE '@|\?|\+|\(|\)|\<|\>|!|\^|\%|\`|\$' 265 strings o1_mf_d3rrgv0l_.ctl|grep -v '[^[:print:]]' 266 strings o1_mf_d3rrgv0l_.ctl|grep -v '[[:print:]]' 267 strings o1_mf_d3rrgv0l_.ctl|grep '[[:print:]]' 268 strings o1_mf_d3rrgv0l_.ctl|grep -v '[[:cntrl:]]' 269 strings o1_mf_d3rrgv0l_.ctl|grep -v '\x{09}' 270 strings o1_mf_d3rrgv0l_.ctl|grep -vP '[^\x00-\x7f]' 271 strings o1_mf_d3rrgv0l_.ctl|tr -dc '\007-\011\012-\015\040-\376' 272 strings -1 o1_mf_d3rrgv0l_.ctl|tr -dc '\007-\011\012-\015\040-\376' 273 strings o1_mf_d3rrgv0l_.ctl|tr -dc '[:print:]\n\r' 274 strings o1_mf_d3rrgv0l_.ctl|grep -vE '@|\?|\+|\(|\)|\<|\>|!|\^|\%|\`|\$' 275 strings o1_mf_d3rrgv0l_.ctl|grep -vE '@|\?|\+|\(|\)|\<|\>|!|\^|\%|\`|\;|\:|\=|\$' 276 strings o1_mf_d3rrgv0l_.ctl|grep -vE '@|\?|\+|\(|\)|\<|\>|!|\^|\%|\`|\;|\:|\=|\$|\"' 277 strings o1_mf_d3rrgv0l_.ctl|grep -vE '@|\?|\+|\(|\)|\<|\>|!|\^|\%|\`|\;|\:|\=|\$|\"|\&|\#' 
grep -vis not the right tool, as it removes entire lines that contain the regular expression. You could trytras shown at unix.stackexchange.com/questions/201751/…, followed bysed. Or start withcat -v, which represents non-printable characters like ^A, then also filter them out withsed. The problem withcat -vis that it doesn't distinguish between a^character and an unprintable character. I am sure there are other solutions.