bash - Convert string in variable lower case -

-

this question has answer here:

using bash version 3.2.57(1)-release (x86_64-apple-darwin14)

how can 're-assign' or 'change' existing value read variable.

if user inputs string iamstring, i'd propinput store value iamstring. i'm printing console example sake.

read userinput echo ${userinput} | tr '[:upper:]' '[:lower:]'

you should store output of echo :

read userinput userinput=$(echo "$userinput" | tr '[:upper:]' '[:lower:]')

Comments

Post a Comment

Popular posts from this blog

C++: Boost interprocess memory mapped file error -

-
i'm trying create memory mapped file using this answer, i'm getting compile errors. code: namespace bi = boost::interprocess; std::string vecfile = "vector.dat"; bi::managed_mapped_file file_vec(bi::open_or_create,vecfile.c_str(), sizeof(struct rectangle) * data_size); typedef bi::allocator<struct rectangle, bi::managed_mapped_file::segment_manager> rect_alloc; typedef std::vector<struct rectangle, rect_alloc> myvec; myvec * vecptr = file_vec.find_or_construct<myvec>("myvector")(file_vec.get_segment_manager()); vecptr->push_back(random_rectangle); the struct this: struct rectangle{ rectangle(float *minarr, float *maxarr, int arr, int exp, int id){ this->arrival = arr; this->expiry = exp; this->id = id; for(int i=0; < 2; i++){ min[i] = minarr[i]; max[i] = maxarr[i]; } int arrival, expiry, id; float min[2]; float max[2]; } the error is: compiler not deduce template argu...
Read more

python - IO.UnsupportedOperation: Not Writable -

-
i have made program stores score attached name in .txt file. however, want print alphabetical order of name attached score. when run program come error io.unsupportedoperation: not writable here code: file = open(class_name , 'r') #opens file in 'append' mode don't delete information name = (name) file.write(str(name + " : " )) #writes information file file.write(str(score)) file.write('\n') linelist = file.readlines() line in sorted(linelist): print(line.rstrip()); file.close() you have opened file read only, attempted write it. file left open, attempt read it, if in append mode, file pointer @ end of file. try instead: class_name = "class.txt" name = "joe" score = 1.5 file = open(class_name , 'a') #opens file in 'append' mode don't delete information name = (n...
Read more

python - Selecting distinct values from a column in Peewee -

-
i looking select values 1 column distinct using peewee. for example if had table organization year company_1 2000 company_1 2001 company_2 2000 .... to return unique values in organization column [i.e. company_1 , company_2 ] i had assumed possible using distinct option documented http://docs.peewee-orm.com/en/latest/peewee/api.html#selectquery.distinct my current code: organizations_returned = organization_db.select().distinct(organization_db.organization_column).execute() item in organizations_returned: print (item.organization_column) does not result in distinct rows returned (it results in e.g. company_1 twice). the other option tried: organization_db.select().distinct([organization_db.organization_column]).execute() included [ ] within disctinct option, although appearing more consistent documentation, resulted in error peewee.operationalerror: near "on": syntax error : am correct in ...
Read more