For this one, the touch command is run, or attempted to run. If it has a zero exit status, then the double pipe OR kicks in, and tries to execute the echo command.
What does double mean in Linux?
A double-dash in a shell command signals the end of options and disables further option processing. … This command outputs all occurrences of the string hello from the specified file.
What does || mean in bash?
Just like && , || is a bash control operator: && means execute the statement which follows only if the preceding statement executed successfully (returned exit code zero). || means execute the statement which follows only if the preceding statement failed (returned a non-zero exit code).
Kuyini ukusetshenziswa kwe-awk ku-Linux?
I-Awk iyinsiza eyenza umhleli akwazi ukubhala izinhlelo ezincane kodwa eziphumelelayo ngendlela yezitatimende ezichaza amaphethini ombhalo okufanele aseshwe kulayini ngamunye wedokhumenti kanye nesenzo okufanele sithathwe lapho okufanayo kutholakala ngaphakathi umugqa. I-Awk isetshenziswa kakhulu ukuskena iphethini nokucubungula.
What is this called in Linux?
Izisekelo ze-Linux Commands
| uphawu | incazelo |
|---|---|
| | | Lokhu kubizwa ngokuthi “Ukugoqa", okuyinqubo yokuqondisa kabusha okukhiphayo komyalo owodwa kokokufaka komunye umyalo. Iwusizo kakhulu futhi ijwayelekile kumasistimu afana ne-Linux/Unix. |
| > | Thatha okukhiphayo komyalo bese ukuqondisa kabusha kufayela (lizobhala phezu kwefayela lonke). |
Ngiyisebenzisa kanjani i-Linux?
Imiyalo ye-Linux
- pwd - Uma uqala ukuvula i-terminal, usuke usohlwini lwasekhaya lomsebenzisi wakho. …
- ls - Sebenzisa umyalo othi "ls" ukuze wazi ukuthi yimaphi amafayela kuhla lwemibhalo okulo. …
- cd - Sebenzisa umyalo "cd" ukuya kuhla lwemibhalo. …
- mkdir & rmdir — Sebenzisa umyalo we-mkdir lapho udinga ukwakha ifolda noma uhla lwemibhalo.
Yiziphi izimvume ezingu-664?
Command line examples
| Umyalo | incazelo |
|---|---|
| chmod 664 global.txt | sets read and write permissions for user and Group, and provides read to Others. |
| chmod 744 Show_myCV.sh | sets read, write, and execute permissions for user, and sets read permission for Group and Others |
Luyini uphawu lwe-bash?
Izinhlamvu ezikhethekile ze-bash nencazelo yazo
| Umlingiswa we-bash okhethekile | Okusho |
|---|---|
| # | # isetshenziselwa ukubeka amazwana umugqa owodwa kusikripthi se-bash |
| $$ | I-$$ isetshenziselwa ukubhekisela ku-id yenqubo yanoma yimuphi umyalo noma iskripthi se-bash |
| $0 | $0 isetshenziselwa ukuthola igama lomyalo kusikripthi se-bash. |
| $name | I-$name izophrinta inani lokuhlukahluka "kwegama" elichazwe kusikripthi. |